# Sticky  Chart Distance x Screen Size - Standards SMPTE and THX



## Peter_

Based on information obtained on the website:
http://myhometheater.homestead.com/v...alculator.html 


I have made a graph with the distances and sizes of screens recommended by the standards SMPTE and THX.


The proportion of the following screen measures is *16:9*. With 1080p content and the measures are the diagonal of the screen.


Differences between the standards:


















*SMPTE*
http://www.smpte.org/ 


Maximum size recommended by standard SMPTE:



















THX
http://www.thx.com/ 


Minimum size of screen recommended by THX:











Screen size recommended by THX:










Viewing Distance when Resolution becomes important:

Screen Size x Viewing Distance

480p

720p

1080p

1440p




















Source: http://www.carltonbale.com/2006/11/1080p-does-matter/ 


Peter


--------------------------------------------------------------------------------------------


Gary Contribution:




> Quote:
> Originally Posted by *Gary Lightfoot* /forum/post/20695274
> 
> 
> This often comes up here and other places, and this diagram is gives a good idea of what viewing angles seating distances will give:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Using image height and width is preferable to diagonal measurements since they're a lot easier to work with, and removes confusion with screen aspect ratio - many people here have 2.35 screens.
> 
> 
> THXs recommended viewing angle for HD 16:9 screens is 40 degrees, or 2.4 image heights. That also works for people with 2.35 screens who use an anamorphic lens, and may work with some pjs that zoom for scope.
> 
> 
> The film industry often recommends 3 x IH for seating distance based on the crossover point between immersion (closer is considered better) and where image artefacts like film grain and projector induced issues become visible. With digital and good HD content that limitation is reduced, and is probably why THX recommend 2.4 x IH rather than 3. Sitting anywhere between 2 to 4 times the Image Height puts you within the usual range of a commercial theatre, and with 1080 displays, we're pretty much there with regards to resolution and image quality.
> 
> 
> As Darin has pointed out, THX often gets misquoted but this video may be of interest:
> 
> http://www.youtube.com/watch?v=rBdmG...embedded#at=50
> 
> 
> I also think it[s worth pointing out that the graphs that say where certain resolutions become noticeable doesn't mean you should sit there. In fact you should probably sit closer because those distances are where the Human eye can start to resolve those resolutions, but when comparing something like a 720 pj to a 1080 pj you might not be able to tell the difference until you get much closer.
> 
> 
> Gary


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## Peter_

I am seated at about 3 metres from the screen and the screen is 76 "wide.


The size of the screen was well on the standard SMPTE and I do not feel any discomfort visual.


I hope these graphics help.


Peter


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## tomdahlberg

They helped me, thanks for pointing me in the right direction!


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## tleavit

hmm.. I basically 5 meters from 133" and have absolutely no problems with it nor anyone else. Even when playing games with mass movement like COD4


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## kevivoe

Peter,


Can you draw a cone showing the minimum and maximum screen sizes? I have 2 rows so how does 1 seat @ 5m help everyone?


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## Peter_




> Quote:
> Originally Posted by *kevivoe* /forum/post/13422516
> 
> 
> Peter,
> 
> 
> Can you draw a cone showing the minimum and maximum screen sizes? I have 2 rows so how does 1 seat @ 5m help everyone?


 http://www.thx.com/home/setup/display.html 












Peter


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## circumstances

are the screen measurements given width or diagonal?


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## Peter_

Diagonal.


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## circumstances

i figured, thanks.


i'll be right around 11 1/2 feet from a 119" screen.


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## Varrius

Very nice and concise info, thanks Peter. This is one of the first things I looked into when researching installing a projector (and have yet to find anything this easy to follow and all in one place), so I'd recommend it for a sticky personally (although I might suggest attempting to convert the units to the american standards, as I believe that is what the majority of people using these forums are used to).


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## Peter_

Thanks Varrius.


It is a good hint. I will convert the units.


Peter.


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## Varrius

Very nice! I had already done the conversion myself (and I'm glad to find out that I'm choosing right about the THX recommended screen size). I'm sure the conversion may help some others, I do hope that I was correct in assuming that many or most of the users here would prefer it in feet instead of meters.


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## Peter_

Picture of the distance of the screen to the ground.











It is about 1.97 feet from the ground and is very comfortable, especially to read the subtitles.


Before, it was about 3 feet, but I was uncomfortable.


Peter


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## crispybacon

Thank you Peter for creating that graph.


I am in the process of designing a 2.35:1 screen. Would you have any idea how the viewing distance would change going from 16:9 to 2.35:1?


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## Peter_

To change the proportion of 16:9 to 2.35:1, simply *multiply* the value of the diagonal of the screen by *0.9472*


For example, the graph shows that to 13.12 feet, the diagonal of the screen in 16:9 must be 97".


Then multiply *97* by *0.9472* which equals approximately *92"* in proportion 2.35:1


Peter.


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## darinp2




> Quote:
> Originally Posted by *Peter_* /forum/post/13317713
> 
> 
> Screen size recommended by THX:



Where did you get that from? If from the 36 degrees recommended by THX then that isn't a recommendation for the screen size you should have, it is a recommendation for the worst case viewing angle in a commercial theater. If a theater was built to that then almost every seat in the house would have a larger viewing angle and THX doesn't tell people where to sit in those theaters (at least from what I've seen). Also, when THX gave a recommendation at their booth at CEDIA last year they said it was based on testing to see where people see pixels with 1080p projectors. But, 1080p projectors vary and then the recommendation wouldn't apply when projectors go beyond 1080p or even to film now. So far I don't recall seeing or hearing anything about THX saying people shouldn't sitting closer than some viewing angle that wasn't based on limited pixel resolution, just stuff about not sitting further away than a certain viewing angle. Put another way, I haven't seen anything from THX limiting how close the closest seats can be in a commercial theater to get certified, only how far away the farthest seats can be.


Thanks for doing these graphs. I just know that the wording of the THX minimum and recommended specs for building a commercial theater have confused a lot of people and that even their later recommendation for home theater was based on limitations of current projectors. I also don't know if they tried using an anamorphic lens, which would generally make pixels less visible at the same viewing ratio.


--Darin


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## Peter_











http://myhometheater.homestead.com/v...alculator.html 

*http://www.cinemaequipmentsales.com/athx2.html* 

http://webvision.med.utah.edu/KallSpatial.html 



Peter.


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## darinp2




> Quote:
> Originally Posted by *Peter_* /forum/post/13694419
> 
> *http://www.cinemaequipmentsales.com/athx2.html*



That supports just what I said:


> Quote:
> The angle subtended by the left and right edges of the Cinemascope image and the *farthest seat in the auditorium* is recommended to be 36 degrees. The minimum acceptable angle is 26 degrees for THX certified cinemas.



This gets paraphrased in other places and people often misconstrue this as THX recommending that people sit at a place where the viewing angle is 36 degrees. That is clearly not the case from what it says about the farthest seat in the theater (this is for commercial theaters with lots of seats). If a commercial theater is built to THX recommendations then the vast majority of people will be sitting in seats with viewing angles larger than 36 degrees.


It is misleading when people say "THX recommended viewing distance" since that 36 degree recommendation is to build a commercial theater so that the minimum viewing angle is 36 degrees, not a recommendation that people sit in the farthest seat if a theater was built to THX recommendations. However, they allow theaters to be THX certified if their minimum is 26 degrees. That is, a minimum for the minimum viewing angle instead of a recommended minimum viewing angle. In both cases it is for the minimum viewing angle in that theater (for multiple seats).


--Darin


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## Peter_

Darin,


Thanks for the explanation.


I'll edit this thread.


Peter.


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## crispybacon




> Quote:
> Originally Posted by *Peter_* /forum/post/13693445
> 
> 
> To change the proportion of 16:9 to 2.35:1, simply *multiply* the value of the diagonal of the screen by *0.9472*
> 
> 
> For example, the graph shows that to 13.12 feet, the diagonal of the screen in 16:9 must be 97".
> 
> 
> Then multiply *97* by *0.9472* which equals approximately *92"* in proportion 2.35:1
> 
> 
> Peter.



Appreciate the math. I'm planing a 130" diagonal so 130 x 0.9472=123" and I plan to sit at around 16' so I'm in the SMPTE maximum zone. I think I better do some testing just in case the screen is too big for the room.


Thanks for the info.


I'm sitting at roughly 180" so thats about x1.5 screen heights


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## CADOBHuK

A green sub?


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## Peter_




> Quote:
> Originally Posted by *CADOBHuK* /forum/post/13705980
> 
> 
> A green sub?



















































Peter.


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## james.92

Peter,


Just wanted to say thanks for your contributions to the projector forums here.


Your photos, graphs, etc. have really been insightful, even to a trigonometry challenged person like myself.


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## Peter_

Thanks James!


Peter.


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## Peter_

New information added.




















Source: http://www.carltonbale.com/2006/11/1080p-does-matter/ 


Peter


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## tleavit

nice find Peter


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## joelbct

Thank you Peter- I had an idea of these numbers, but it is very nice to see it all laid out in a concrete format. This should prove useful on future projects-


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## Peter_

I did think this thread could be fixed. Because these standards are not old. But I'm not a moderator to decide about it.


I'll be watching this thread and I'll trying to help as much as I can.


Peter


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## Gary Lightfoot


This often comes up here and other places, and this diagram gives a good idea of what viewing angles certain seating distances will give:











Using image height is preferable to diagonal measurements since they're a lot easier to work with, and removes confusion with screen aspect ratio - many people here have 2.35 screens and using the height works for 16:9 and 2.35 when using an A lens.


THXs recommended viewing angle for HD 16:9 screens is 40 degrees, or 2.4 image heights. That also works for people with 2.35 screens who use an anamorphic lens, and may work with some pjs that zoom for scope. Sitting at 2.4 SH for 16:9 is 40 degrees and 52 degrees for 2.35 from the same seat.


The film industry used to recommend 3 x IH for seating distance based on the crossover point between immersion (closer is considered better) and where image artefacts like film grain and projector induced issues become visible. With digital and good HD content that limitation is reduced, and is probably why THX recommend 2.4 x IH (52 degrees) rather than 3 X IH. Sitting anywhere between 2 to 4 times the Image Height puts you within the usual range of a commercial theatre, and with 1080 displays, we're pretty much there with regards to resolution and image quality.


As Darin has pointed out, THX often gets misquoted so this video may be of interest:

http://www.youtube.com/watch?v=rBdmG...embedded#at=50 


I also think it's worth pointing out that the graphs that say where certain resolutions become noticeable doesn't mean you should sit there. In fact you should probably sit closer because those distances are where the Human eye can start to resolve those resolutions, so sitting closer means those resolutions become more visible and detail visibly clearer. If you sit at the threshold of visibility of lets say 1080 and then comparing it to 720 from the same distance (all else being equal), you might not be able to tell the difference between the two until you get much closer.


Gary


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## Peter_

I really appreciated your post (contribution) to this thread.


I'll quote your post in the first page.


Thank you,


Peter


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## scarpenter002

Peter,


Thanks for all the great information. You need to convince the moderators to make this a sticky thread.


Cheers,

Scott


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## millerwill

These charts and tables for good starting points, but viewing distance is a very personal thing, with wide variation in preferences. E.g., with a 2.35 screen I have seen many people report liking to sit ~ 1 screen width away ((53 deg viewing angle). This is a bit too close for me; I sit ~ 12.5 ft from a 12 ft W 2.35 pic (51 deg angle). For a 16x9 pic, from this same viewing distance, my viewing angle is 46 deg, which I fine good. I.e., I like a very immersive pic, but others fine it better with smaller viewing angles.


And I agree with Darin, that viewing angle [2*arctan(.5/SW), where SW is the viewing distance divided by the screen width] is the more useful parameter to discuss.


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## William1984




> Quote:
> Originally Posted by *tomdahlberg* /forum/post/13362578
> 
> 
> They helped me, thanks for pointing me in the right direction!



yeah it helped me too.


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## audionewer

i am wondering which standard i shall go with? THX or SMPTE?


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## Peter_




> Quote:
> Originally Posted by *audionewer* /forum/post/21882662
> 
> 
> i am wondering which standard i shall go with? THX or SMPTE?



These standards help to start, but can not be used as definitive.


Make some tests with a white cloth, so you can increase or decrease the size of the image until you find the right size for you and your family.











Best regards,

Peter


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## audionewer

i got 100inches 1.3 gain screen. i have to shrink it a little bit ( 92inches). i sit about 11 ft from the screen right now. i hope that is okay.


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## Peter_




> Quote:
> Originally Posted by *audionewer* /forum/post/21883073
> 
> 
> i got 100inches 1.3 gain screen. i have to shrink it a little bit ( 92inches). i sit about 11 ft from the screen right now. i hope that is okay.



I think it is ok.

it is inside the SMPTE Standard.

I prefer the SMPTE instead of THX.


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## mtbdudex

Bump with new info:

I was posting in this thread, Will I See Pixels? , and saw new chart with 4k added to Carlton Bale website.

Saw it was not in this thread, the "old" 1440p was posted, so posted here as well.


> Quote:
> Originally Posted by *mtbdudex*  /t/1433660/will-i-see-pixels#post_22489661
> 
> 
> There is also this chart, when I was designing my home theater it was helpful, I overlaid my viewing distance on LH axis and intended screen size bottom axis.
> 
> Then you know what zone you fall into.
> 
> (yea, being an engineer we do this daily)
> 
> 
> More info here Chart Distance x Screen Size - Standards SMPTE and THX
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Ok; it's been so long since I used it (2007), I see chart has been updated for 4k, cool.
> http://carltonbale.com/


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## Peter_

Thank you, Mike.


Excellent Addition.


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## mtbdudex




> Quote:
> Originally Posted by *Peter_*  /t/1004723/chart-distance-x-screen-size-standards-smpte-and-thx/30#post_22489777
> 
> 
> Thank you, Mike.
> 
> 
> Excellent Addition.


I try to point people to the info/data so they can grasp the "why things are they way they are" and reach their own conclusions instead of just telling them.

Your thread is a perfect example of that, give info and let them grasp.


Side note1;for those who took thermodynamics, remember your charts/tables used to explain the state of matter? (solid-liquid-gas)









and Pressure vs volume (lines of constant temp) ......or Temp vs Volume?(lines of constant pressure)
























Now those took a while to use proficiently.....


Side note2: What is the only element that crystallizes from the top > down?

And why is that so important?


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## mtbdudex

I promise this will be my only OT post here.....

Where are all the engineering geeks?

For sure I would have thought someone would have posted by now


> Quote:
> Side note2: What is the only element that crystallizes from the top > down?
> 
> And why is that so important?



H20

Ice rinks would not be possible, nor would life be able to sustain in ponds/lakes in the winter.


H20 is the only element that as it drops in temperature and nears it's phase change gets less dense.......so cold water only falls until 39deg f or so, then it rises and at 32deg crystalizes and then floats on top of its liquid self.

All other compounds don't do that.

Ask any mold engineer what the shrinkage rate it for something when it changes phase, and thy have to take that into account.


If H20 did not do that, then ponds would freeze from the bottom up and all life in it would cease to have a place to exist.

Don't you think that is kinda neat...who engineered it to be so?

Of all the compounds only water does that, why?


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## bigdogaxis

I got to the party too late. While I am not an engineer, ice seemed the logical choice.


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## dchandwani

These are very useful charts. Does anyone know what will be the difference with JVC X55 eshift on seating distance ?


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## CAVX

  
 


I hope this helps. I am into CIH (Constant Image Height) and created this really easy to use diagram in Sketch Up. This is based on that chart that Gary posted on page 1 and is how I work out screen sized and seating distances.


The two images are the same, I have just scaled the 2nd up to 2x the size keeping the girl at 1:1 for a scale reference.


Both take the room length and divide that by 4 to find an ideal screen height. This was actually the recommended method back by CEDIA in the 1.33:1 days and works perfectly well today.

.

The screen height is then used for both finding the width (by multipling by what AR you desire) and the seating distances. In the chart posted by Gary, there is a minimum of 2x the image height recommendation by SMPTE. This can also be found on the Disney WOW Blu-ray and in real life experience (from someone that actually sits at this distance in their own cinema), it is very immersive.


There has been discussion about the THX 36 degree recommendation as well. Based on the chart posted by Gary, 36 degrees is about 3.68x the image height (for CinemaScope 2.39:1) and I have used that to find the farthest distance from the screen. Note it leaves a gap between the back seats and the back wall.


To keep it really simple, divide your room by 4 to find the image height. You sit NO closer than 2x and NO farther than 3.68x and you can feel free to sit ANYWHERE in between you want.


I have used the mid point between 2x and 3.68x to find the centre of the surround field. I have used equal spacing of 60 degrees between each surround. Even if seated behind the side LS/RS, you will still get good envelopment from a 7.1 system because you are still in the sound field.


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## BillFree

I need help on size of fixed screen for my home theater. My room is 14.5 ft x 18 ft. projector is mounted on back wall (18ft). Our 4 HTchairs are 16 ft. We watch 4.3,1.85,2:35 movies using Dtheater Dvhs, laserdisc's,.HD-DVD, Blueray OPPO 105 players.

My projected screen on a white wall from a EW270E projector is 122x74. watching men in black(1.85) bluray it is 122x66. It seems t be just right. Based on your THX figures, what size fixed screen would you recommend? I hope to upgrade to a 1080p/4k projector someday. I would appreciate your help.


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## millerwill

I would recommend getting as wide a screen as you can fit on your front wall. E.g., my room is almost the same size as yours, though 144" is the widest screen I could fit (due to speakers, etc.). For 2.35 pkcs this thus gives a pic ~ 61" high. For 16x9 HDTV, though, it would be 81" high, which is too much for my viewing distance. I settled on 72" high for a 16x9 pic, which gives a 128" wide pic.


SO, I went with a screen 144" x 72". For 2.35 pics, I zoom the pic to be 144" wide and have a 'black bar' ~11" high across the top (since I lens shift the pic to line up with the bottom of the screen). For 16x9 pics, I zoom to fill up the 72" height and have a 'black bar' 16" wide on one side of the screen that I mask with a panel with black absorbing material. (Having a projector that has zoom and lens shift memory makes this especially simple.)


This works great for me, but you may come up with a better solution for yourself. Be creative and think about all the possibilities--that's the fun part of doing HT!


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## CAVX

You really need to work off image or screen height, not the width.


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## lanlishi

i think so,good,i'll be right around 11 1/2 feet from a 119" screen. thank you


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## dark41

I just want to say thanks for all the work put into this. I had no idea that I should be sitting so close to a 55" screen.


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## dougri

Do any of the guidelines change for 3D content? I've only had a 3D projector for a few days, but I find that 3D is a tradeoff for me between immersion and the ability to focus on pop-out objects. If only depth cues are used, I prefer a larger screen with 3D than with 2D, but that is limited by my ability to focus on the popout effects... in some scenes I have to scoot back a few feet to focus (e.g. on some of the foreground fish in imax under the sea). Ignoring the pop out focus issue, I prefer just over 2x screen heights for 3D and just under 3x for 2D. Curious if anyone else has dealt with this tradeoff in deciding on a screen purchase.


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## Gary Lightfoot

I guess in one respect it doesn't change because the theatre seating remains the same whether or not the presentation is 3D or not. That may help with the focus issues you're having but that doesn't really help overall.


I think you've come to the same conclusion I did. I prefer closer seating distances, and I too think that for 3D to work well, you do need to be close(r) to the screen. When a 3D image hits the screen border and is quite visible when it does it, the 3D illusion collapses. I really noticed this with Avatar because I was not able to sit in my usual seat, and was sat further back. I found the movie was less immersive or involving, and the 3D didn't really add anything, especially when the effect hit the borders, where it brought attention to itself as a distraction. Not the best movie experience for me.


I'm sure not everyone feels the same, but for me, you need to be close enough for the 3D to remain as intact as possible. So I guess that IMAX is probably the best format for 3D to work at its best. At home with CIH, for some of us it's going to be a bit of a compromise.


To get the best from a CIH set up, you should set up for 16:9 - make sure you are sat close enough so that 16:9 is as big as you can comfortably watch, and then 2.35 should be wider and more immersive, as designed. If you do it the other way round or don't take 16:9 into account when deciding on the screen size and seating distance, you will find 16:9 looks too small and may be tempted to zoom it larger on the 2.35 screen. 3D seems to add another variable into the mix for some of us.


If we use a 16:9 screen with top and bottom masking and use it as a 2.35 screen most of the time (and with normal 16:9 content within it, and sat suitably close), you could use the full height of the screen for the occasional IMAX movie or 3D, but that could be a problem finding a pj that can fill the screen for all circumstances, and being able to zoom enough and then not have (source or display) pixel visibility issues as well.


Gary


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## jtl46

Hopefully people are still responding to this thread. I am now getting reading order my first pj and screen and I am not sure I really understand as much as I thought. My projector of choice is a Benq 1080ST essentially because I have a good spot on the ceiling to mount it. I am limited to 13' or less for my seating. I was going to purchase a 110" 16:9 diagonal screen but after looking at the charts in this thread I wonder if that is too large, if so I could get a 100". I am also confused about projecting 2:35 images. Will this just show bars on the top and bottom of my screen like they do on my HDTV? On my TV I just zoom the image to fill the screen, but I was told to put my projector on max zoom before I establish the throw distance. If I do this I will not be able to enlarge the picture for 2:35 content or am I missing something. Thanks.


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## Gary Lightfoot

Been having a little trouble posting, and had a few failed attempts, but here goes...


A 16:9 screen is just like a big tv, so a 2.35 movie will have black bars top and bottom the same as on your tv. It means that 2.35 films look considerably smaller than they could with a 2,35 screen and correct seating distance for immersion.


If you have the projector, you can experiment to see what sizes work best for you, but I would try for a 2.35 screen if the pj has a zoom of over 1.33 and can lens shift to keep the image on the screen. Without lens shift the image may move off the screen top or bottom, so you need to experiment.


If you zoom, you have to experiment with seating distance to make sure that pixel size doesn't become a problem when you zoom larger for scope.


Three times the screen height for the 2.35 image may be a reasonable starting point to get you going, and experiment with moving the seating forward and backward for scope movies to see what works best and deciding on where to keep your seats, but I would ensure that both scope and 16:9 works for you before buying a screen.

Gary


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## nathan_h




> Quote:
> Originally Posted by *CAVX*  /t/1004723/chart-distance-x-screen-size-standards-smpte-and-thx/30#post_23037150
> 
> 
> 
> 
> 
> I hope this helps. I am into CIH (Constant Image Height) and created this really easy to use diagram in Sketch Up. This is based on that chart that Gary posted on page 1 and is how I work out screen sized and seating distances.
> 
> 
> The two images are the same, I have just scaled the 2nd up to 2x the size keeping the girl at 1:1 for a scale reference.
> 
> 
> Both take the room length and divide that by 4 to find an ideal screen height. This was actually the recommended method back by CEDIA in the 1.33:1 days and works perfectly well today.
> 
> .
> 
> The screen height is then used for both finding the width (by multipling by what AR you desire) and the seating distances. In the chart posted by Gary, there is a minimum of 2x the image height recommendation by SMPTE. This can also be found on the Disney WOW Blu-ray and in real life experience (from someone that actually sits at this distance in their own cinema), it is very immersive.
> 
> 
> There has been discussion about the THX 36 degree recommendation as well. Based on the chart posted by Gary, 36 degrees is about 3.68x the image height (for CinemaScope 2.39:1) and I have used that to find the farthest distance from the screen. Note it leaves a gap between the back seats and the back wall.
> 
> 
> To keep it really simple, divide your room by 4 to find the image height. You sit NO closer than 2x and NO farther than 3.68x and you can feel free to sit ANYWHERE in between you want.
> 
> 
> I have used the mid point between 2x and 3.68x to find the centre of the surround field. I have used equal spacing of 60 degrees between each surround. Even if seated behind the side LS/RS, you will still get good envelopment from a 7.1 system because you are still in the sound field.



This is very cool math.


For example, my room is 16' deep, 12' wide. So my 2.35:1 screen should be 48" tall according to your system.


My screen is 120" wide 2.35:1 so it's 51" high. And you know what? I've mostly lived with it masked down to.... wait for it.... 47" tall (or as small as 40" tall with some speakers) which is within the sweet spot of this calc.


Wish I had seen this post back when planning instead of learning through trial and error


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## nathan_h




> Quote:
> Originally Posted by *dchandwani*  /t/1004723/chart-distance-x-screen-size-standards-smpte-and-thx/30#post_22732192
> 
> 
> These are very useful charts. Does anyone know what will be the difference with JVC X55 eshift on seating distance ?



While the eshift does make visible pixel structure almost a complete non issue no matter one's distance from the screen, it doesn't actually change much about the distance recommendations, since even with 1080p the recommendations are based mostly on how much of one's field of view is occupied, without regard for visible pixel structure in most instances.


----------



## CAVX




> Quote:
> Originally Posted by *dougri*  /t/1004723/chart-distance-x-screen-size-standards-smpte-and-thx/30#post_23895727
> 
> 
> Do any of the guidelines change for 3D content?



It was actually the testing of a 3D projector (Mitsubishi HC9000) that led me to want to sit 2x the image height. I started out the day in my back row, just found that (and apparently I am not the only one here) a 3D image at a given size looks smaller than the same image in 2D on the same screen. So I jumped to the front row and found it to be great. I then decided to sit there for 2D and now the front row is "the best seats" in the house. My kids don't like being that close and will always ask if they can sit in the back row.



> Quote:
> Originally Posted by *nathan_h*  /t/1004723/chart-distance-x-screen-size-standards-smpte-and-thx/30#post_24348041
> 
> 
> This is very cool math.



Thank you


----------



## Gary Lightfoot




> Quote:
> Originally Posted by *nathan_h*  /t/1004723/chart-distance-x-screen-size-standards-smpte-and-thx/30#post_24350959
> 
> 
> 
> 
> Quote:
> Originally Posted by *dchandwani*  /t/1004723/chart-distance-x-screen-size-standards-smpte-and-thx/30#post_22732192
> 
> 
> These are very useful charts. Does anyone know what will be the difference with JVC X55 eshift on seating distance ?
> 
> 
> 
> 
> While the eshift does make visible pixel structure almost a complete non issue no matter one's distance from the screen, it doesn't actually change much about the distance recommendations, since even with 1080p the recommendations are based mostly on how much of one's field of view is occupied, without regard for visible pixel structure in most instances.
Click to expand...


Actually, the recommendations from the charts take into account picture quality as well as immersion. For example, Fox determined back in the 50s that a 45 degrees horizontal viewing angle for scope (3 x the screen height) was the optimal viewing distance for film based on the crossover point where image quality deficiencies (film grain, projector mechanics) start to become visible with how close we could sit for better involvement (immersion). Back in 2000 Dolby produced a white paper that suggested that with improved film grain and perhaps better projectors, sitting closer to around 50 degrees would be possible. As it turns out, THX recommend 52 degrees for scope (40 degrees for 16:9 in the same seat for a CIH set up) with good quality HD material as their optimal viewing distance. That's around 2.4 x SH. This is probably dues to the better image quality and less projector mechanical artifacts that digital presentations give us compared to film.


So, if eshift improves image quality by reducing any visible artifacts, then it can be used in conjunction with closer seating distances because immersion is determined to be 'a good thing', and the quality/immersion crossover point allows closer seating distances if the individual wants that.


Gary


----------



## Curamrda


a am little bit loosing int the schemas... what is the max screen for me, when I can watch from 4m ?


----------



## nathan_h




> Quote:
> Originally Posted by *Curamrda*  /t/1004723/chart-distance-x-screen-size-standards-smpte-and-thx/30#post_24614107
> 
> 
> a am little bit loosing int the schemas... what is the max screen for me, when I can watch from 4m ?



What aspect ratio are you using? 2.35:1 or 16:9 or something else? This will help people answer the question.


Useful info, but less important: What is the source? 1080p, 720p, UHD/"4k"? This will help people refine their answers.


How many rows of seats?


My view would be to have a 4m WIDE (not diagonal) 2.35:1 screen as my maximum size in your situation, without knowing anything else.


----------



## Curamrda


sorry. it will be 16:9 1080p. one row seats


----------



## nathan_h

I would recommend about twice the height of the screen = the distance from the screen. so a screen of no more than 2 meters tall. So about 3 meter across (not diagonal) would be about the largest I would attempt.


Speaker placement then becomes a challenge, of course, so people with that large a screen often get an acoustically transparent screen and place the speaker behind it. You can reach some of the discussions about that.


----------



## oOOBillO0o




> Quote:
> Originally Posted by *Peter_*  /t/1004723/chart-distance-x-screen-size-standards-smpte-and-thx/0_100#post_13636821
> 
> http://www.thx.com/home/setup/display.html
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Peter



Sorry, I still don't understand.


What I am looking for is, where on the wall do I put the screen?


If I am sitting back 6.5 feet, with a my eye height at 39 inches, the, THX recommended, top of the screen should not be higher than 60 inches? (tan 15 * 78 inches = 20.9, then rounded to 21. 21 + 39 = 60")


Am I doing it right?


(52" Sony LCD HDTV)


----------



## jrcrunch

i will have 2 rows of seating

what is the maximum and minimum distance for watching on a 120 inch screen with a 4k projector screen?


----------



## Gary Lightfoot

jrcrunch said:


> i will have 2 rows of seating
> 
> what is the maximum and minimum distance for watching on a 120 inch screen with a 4k projector screen?


If your screen is 120 inch diagonal 16:9, then your screen height is 58.8 inches.

Ultimately it's down to personal preference and comfort, so experimentation is the best way to find out how close you can comfortably sit for long periods with the screen you have at the height it is mounted - the closer you sit the greater the vertical viewing angle becomes. 15 degrees is the recommended vertical viewing angle for comfort, but 35 degrees is the recommended maximum, so there is leeway there.

As for a viewing distance 'range' for 4k, Sony recommend a 1.5 x Screen Height seating distance ratio for 4K, so to get the range you could approach it in one of two ways provided that you are watching 1080 upscaled to 4k since that currently all your source material is probably 1080, and I would think that would be the limitation from a source quality perspective.

Combine Sonys recommendation with THXs recommended range of 2.4 x SH (optimal) to 3.68 x SH (back row) which is based on viewing angles/immersion, and their front row limitation appearing to hinge on good quality 1080, to give you a range of 1.5 to 3.68.

Or reduce the back row by a similar amount as the front based on Sonys recommendation to give you something like 1.5SH 2.78SH.

But the closer seating distance will rely on good quality source material.

Having said that, THX have also said that they feel that a 60 degree viewing angle (2xSH) is probably too wide for films (this is also SPMTEs closest recommended seating distance), but I'm not sure if they are basing that on a comfort perspective (too much eye movement) or an image quality perspective. Maybe a combination of the two.

Considering you're using upscaled 1080 rather than 4k as your source material, that may ultimately determine how close you want to sit, so we're back to experimenting to see what works best for you.



HTH

Gary


----------



## yodatodd

*New Theater*

Hi all. So if this is painfully obvious and I am just too dense to recognize it, please forgive me. But I am building a new home with a dedicated theater room, and I am uncertain my ideal screen size for the space. 

Projector is Sony VLP-HW40ES and can be mounted anywhere I would like (suggestions on THAT would be much appreciated too!)

Room dimensions: 14' (where screen would go) x 20', with platform for two rows of seating approximately 13' back from the screen wall. 

Should I go with a 100" or 120" screen?\

Thank you!


----------



## anthonybuchanan

I really do get why people rely more on a white paper done by someone they do not know that made conclusions based on criteria that they don't know versus what they see with their own eyes.

Rather than use these types of charts to run your life you should:

1. Setup your projector at different locations in the room.
2. Change the zoom to different sizes of screen.
3. Sit at different distances from the screen.

Then make a decision based on what you see and what you yourself like. This is a far better approach than letting these guys tell you what to like. Hope this helps.


----------



## Gary Lightfoot

anthonybuchanan said:


> I really do get why people rely more on a white paper done by someone they do not know that made conclusions based on criteria that they don't know versus what they see with their own eyes.
> 
> Rather than use these types of charts to run your life you should:
> 
> 1. Setup your projector at different locations in the room.
> 2. Change the zoom to different sizes of screen.
> 3. Sit at different distances from the screen.
> 
> Then make a decision based on what you see and what you yourself like. This is a far better approach than letting these guys tell you what to like. Hope this helps.


Oh the irony


----------



## anthonybuchanan

anthonybuchanan said:


> I really do get why people rely more on a white paper done by someone they do not know that made conclusions based on criteria that they don't know versus what they see with their own eyes.
> 
> Rather than use these types of charts to run your life you should:
> 
> 1. Setup your projector at different locations in the room.
> 2. Change the zoom to different sizes of screen.
> 3. Sit at different distances from the screen.
> 
> Then make a decision based on what you see and what you yourself like. This is a far better approach than letting these guys tell you what to like. Hope this helps.


Typo above. 

I DON'T get it.


----------



## rboster

The standards set from groups like SMPTE and THX involve the science behind motion picture images. I think most view them as the starting point for seeking the most accurate image from their projector/screen. Tweaking those standards to fit personal preferences or the inherit compromises most of us use to adapt to our individual situations is part of the process.

For those interested in learning more about SMPTE (Society of Motion Picture & Television Engineers) here's a link to their site:

https://www.smpte.org/about


----------



## anthonybuchanan

rboster said:


> The standards set from groups like SMPTE and THX involve the science behind motion picture images. I think most view them as the starting point for seeking the most accurate image from their projector/screen. Tweaking those standards to fit personal preferences or the inherit compromises most of us use to adapt to our individual situations is part of the process.
> 
> For those interested in learning more about SMPTE (Society of Motion Picture & Television Engineers) here's a link to their site:
> 
> https://www.smpte.org/about


I just can't help but think that everything they suggest is just based on their own personal preference. 

It just seems like a "make work" job they have versus something really useful and concrete such as CR research done by people like Darin. 

Do they actually say my 130" diagonal 2.39 screen is NOT enjoyable at my preferred 6' to 7.5' viewing distance? Do they say that?


----------



## bud16415

anthonybuchanan said:


> I DON'T get it.


Pants come in all sizes but only one size fits each one of us comfortably. If you are designing a movie theater you have to have an abundance of seats roughly distributed in a range similar to what people like. There are outliers to any normal distribution data set. Sounds like you are one of those points. A size 58” waist is such a pair of pants and so is a 24” you can’t expect a store to stock too many of those sizes. 

These outfits are just setting guidelines not rules for individuals. You can sit as close as you like. If you are advising someone you should shoot for the middle as a starting point. Knowing you may be on the end of the bell curve yourself. After you tell them the starting point I like your advice of finding your own place.


----------



## rboster

anthonybuchanan said:


> I just can't help but think that everything they suggest is just based on their own personal preference.
> 
> It just seems like a "make work" job they have versus something really useful and concrete such as CR research done by people like Darin.
> 
> Do they actually say my 130" diagonal 2.39 screen is NOT enjoyable at my preferred 6' to 7.5' viewing distance? Do they say that?


They have been around for 100 years and recognized by the film and TV industry as the standard bearers. If you chose to abide by their recommendations or don't abide by them, it's your call. 

The important criteria to use is what you and those viewing your screen enjoy...that's the only set of standards you need to use. BUT, just because you chose to believe the Motion Picture and Television standards are wrong doesn't make it so....chose to believe or not believe. This isn't a "truther" debate.


----------



## Craig Peer

yodatodd said:


> Hi all. So if this is painfully obvious and I am just too dense to recognize it, please forgive me. But I am building a new home with a dedicated theater room, and I am uncertain my ideal screen size for the space.
> 
> Projector is Sony VLP-HW40ES and can be mounted anywhere I would like (suggestions on THAT would be much appreciated too!)
> 
> Room dimensions: 14' (where screen would go) x 20', with platform for two rows of seating approximately 13' back from the screen wall.
> 
> Should I go with a 100" or 120" screen?\
> 
> Thank you!


I certainly would not go 100" - 120" would be better, if your first row is 13' back. I sit 11' 3" from a 122" diagonal 16:9 screen. It's not too big. But you could set up your projector and experiment on the wall too. Make sure you factor in where your speakers will go. Give us a call for screen quotes if you would like.


----------



## Gary Lightfoot

anthonybuchanan said:


> I just can't help but think that everything they suggest is just based on their own personal preference.
> 
> It just seems like a "make work" job they have versus something really useful and concrete such as CR research done by people like Darin.


That's quite funny. Darin himself refers to the likes of THX and SMPTE from time to time because they have been doing research and making standards in the subject too, and for quite some time. 



anthonybuchanan said:


> Do they actually say my 130" diagonal 2.39 screen is NOT enjoyable at my preferred 6' to 7.5' viewing distance? Do they say that?


No, they're guidelines and are just that - you can do what ever you like to suit your own personal preferences, but what you have to be aware of is that many people don't realise how close they can sit to a projected image if they want to. Having the data from SMPTE etc to hand puts things into perspective and allows people to see what kind of range the seating is in a commercial theatre, and they can use that as a guide to what they can do at home (or measure out where they sit in a commercial theatre and replicate that). You'll be surprised how many people buy what they think is a big screen (it's bigger than their tv so it's 'big') and sit at the back of the room which is often the equivalent of beyond the back row of a commercial theatre. Over on another forum, there was a guy who for around 8 years would constantly argue that people couldn't and shouldn't sit closer than 3xSH because of various nonsensical reasons. There are some strange people out there...

Did you know that 3xSH was originally determined by film quality/projector mechanics vs immersion/closer seating/visual acuity back in the very early 50s? It's due to research. THX did similar research back in the early 80s to arrive at their recommendations. But they're just that - recommendations, they're not telling you to sit there.

Some people like to understand where the recommendations come from rather than blindly follow, despite the heritage of the source data, so for some it's an interesting subject to look into more deeply.

I prefer sitting closer than the guidelines after testing how close I like to sit, but the info from the likes of THX etc helped me get there, though ultimately I had to wait for 1080 to arrive before I could do that. Sometimes the technology is the limiting factor (just like film was back in the 50s).

That's why you often see us telling people to experiment by projecting onto a wall and testing different sizes and aspect ratios along with different seating distances so they can arrive at something that suits their personal preferences. They often need to be told they can sit a lot closer than they think though.

Gary


----------



## anthonybuchanan

rboster said:


> They have been around for 100 years and recognized by the film and TV industry as the standard bearers. If you chose to abide by their recommendations or don't abide by them, it's your call.
> 
> The important criteria to use is what you and those viewing your screen enjoy...that's the only set of standards you need to use. BUT, just because you chose to believe the Motion Picture and Television standards are wrong doesn't make it so....chose to believe or not believe. This isn't a "truther" debate.


I never said these smart people were wrong.


Never said that.


----------



## erkq

anthonybuchanan said:


> I really do get why people rely more on a white paper done by someone they do not know that made conclusions based on criteria that they don't know versus what they see with their own eyes.
> ...


This discussion seems to be going in an OK direction. But I do want to point out that we *do *know the criteria used. THX and SMPTE are very explicit about how they arrive at their recommendations.


----------



## anthonybuchanan

Gary Lightfoot said:


> That's quite funny. Darin himself refers to the likes of THX and SMPTE from time to time because they have been doing research and making standards in the subject too, and for quite some time.
> 
> 
> 
> No, they're guidelines and are just that - you can do what ever you like to suit your own personal preferences, but what you have to be aware of is that many people don't realise how close they can sit to a projected image if they want to. Having the data from SMPTE etc to hand puts things into perspective and allows people to see what kind of range the seating is in a commercial theatre, and they can use that as a guide to what they can do at home (or measure out where they sit in a commercial theatre and replicate that). You'll be surprised how many people buy what they think is a big screen (it's bigger than their tv so it's 'big') and sit at the back of the room which is often the equivalent of beyond the back row of a commercial theatre. Over on another forum, there was a guy who for around 8 years would constantly argue that people couldn't and shouldn't sit closer than 3xSH because of various nonsensical reasons. There are some strange people out there...
> 
> Did you know that 3xSH was originally determined by film quality/projector mechanics vs immersion/closer seating/visual acuity back in the very early 50s? It's due to research. THX did similar research back in the early 80s to arrive at their recommendations. But they're just that - recommendations, they're not telling you to sit there.
> 
> Some people like to understand where the recommendations come from rather than blindly follow, despite the heritage of the source data, so for some it's an interesting subject to look into more deeply.
> 
> I prefer sitting closer than the guidelines after testing how close I like to sit, but the info from the likes of THX etc helped me get there, though ultimately I had to wait for 1080 to arrive before I could do that. Sometimes the technology is the limiting factor (just like film was back in the 50s).
> 
> That's why you often see us telling people to experiment by projecting onto a wall and testing different sizes and aspect ratios along with different seating distances so they can arrive at something that suits their personal preferences. They often need to be told they can sit a lot closer than they think though.
> 
> Gary


 
I hear you brother. Amen.


I should have maybe just said in the beginning there are other HT recommendations that are more important than this one.


I know these people are 10 times smarter than I am and they have done some really important stuff it just seems like this one is one of those where one of the bosses said, 


Boss: "Hey Hendersen what are you working on today".
Hendersen: "I just finished the project you had me working on".
Boss: "What are you working on next?"
Hendersen: "My week is clear I don't have any other projects I was thinking of going to the beach".
Boss: "What? You're going to the beach?"
Boss: "Makeup some damn white paper and tell people where to sit in their HT".
Boss: "And put our seal on it to make it real official like".
Hendersen: "Okay boss".


----------



## rboster

anthonybuchanan said:


> I never said these smart people were wrong.
> 
> 
> Never said that.





anthonybuchanan said:


> I hear you brother. Amen.
> 
> 
> I should have maybe just said in the beginning there are other HT recommendations that are more important than this one.
> 
> 
> I know these people are 10 times smarter than I am and they have done some really important stuff it just seems like this one is one of those where one of the bosses said,
> 
> 
> Boss: "Hey Hendersen what are you working on today".
> Hendersen: "I just finished the project you had me working on".
> Boss: "What are you working on next?"
> Hendersen: "My week is clear I don't have any other projects I was thinking of going to the beach".
> Boss: "What? You're going to the beach?"
> Boss: "Makeup some damn white paper and tell people where to sit in their HT".
> Boss: "And put our seal on it to make it real official like".
> Hendersen: "Okay boss".


Again, they didn't pull these standards out of thin air....it's based on testing and science over the last 100 years. I'd love to see links that discredits the SMPTE. 

I'll leave this discussion by quoting Lincoln:

"Better to remain silent and be thought a fool than to speak out and remove all doubt."


----------



## anthonybuchanan

rboster said:


> Again, they didn't pull these standards out of thin air....it's based on testing and science over the last 100 years. I'd love to see links that discredits the SMPTE.
> 
> I'll leave this discussion by quoting Lincoln:
> 
> "Better to remain silent and be thought a fool than to speak out and remove all doubt."


I will report this cheap shot to the moderator. 

If you belive this seating chart is any more than........ then your cheap shot applies to you and only you.

Think for yourself.


----------



## erkq

anthonybuchanan said:


> I will report this cheap shot to the moderator.
> 
> ...


Rboster used to be a moderator himself. I'm sure he knows the limits.


----------



## anthonybuchanan

erkq said:


> Rboster used to be a moderator himself. I'm sure he knows the limits.


People know limits and violate them all the time.


----------



## darinp2

erkq said:


> THX and SMPTE are very explicit about how they arrive at their recommendations.


Have they been? I recall that I had to ask THX at a tradeshow how they came up with their number and I don't recall them making it public that they used a 1080p display and had people move back until they couldn't see pixels anymore. Lots of things a claimed to be scientific, but when you find you how they did their testing their results aren't quite as solid for different situations as some people seem to think.

Another problem is misinterpreting what a standard means. I haven't read the previous posts close enough to see if some people are still making the mistake of thinking that a particular recommended viewing ratio for commercial theaters was a recommendation for the best viewing ratio, when it said nothing about larger angles being worse, especially when a recommendation for the smallest viewing ratio for any theater in a particular commercial theater means that average seats have a much larger viewing ratio than the recommended value.

--Darin


----------



## anthonybuchanan

Thus is too funny. 

This rbooater character is even making claims that Lincoln made quotes that are not even Lincolns quotes. 

Read this. 
http://quoteinvestigator.com/2010/05/17/remain-silent/

How can we beleive roasters seating charts if he can't even shoot straight with quotes.


----------



## erkq

darinp2 said:


> Have they been? I recall that I had to ask THX at a tradeshow how they came up with their number and I don't recall them making it public that they used a 1080p display and had people move back until they couldn't see pixels anymore. Lots of things a claimed to be scientific, but when you find you how they did their testing their results aren't quite as solid for different situations as some people seem to think.
> 
> Another problem is misinterpreting what a standard means. I haven't read the previous posts close enough to see if some people are still making the mistake of thinking that a particular recommended viewing ratio for commercial theaters was a recommendation for the best viewing ratio, when it said nothing about larger angles being worse, especially when a recommendation for the smallest viewing ratio for any theater in a particular commercial theater means that average seats have a much larger viewing ratio than the recommended value.
> 
> --Darin


EDIT: Wait... Darinp2? What gives? I thought I was responding to Anthony. You've been around *forever *and know *a lot*! How is this confusing?

Guys at trade shows aren't known to be fountains of technical knowledge.

Recommendations are given in degrees of viewing angle (what I assume you mean by viewing ratio). They are given as a range, not a single value. This governs where the frontmost and rearmost row can go for a given screen size. It's all very clearly presented and from your confused writing about your confusion I can only surmise you have never even looked at them. If you had, you would not be so confused.


----------



## millerwill

My recommendation is to forget about SMPTE and THX and to decide for yourself. Sony recommends (for 4K) to sit up to 1.6 picture heights from the screen, but this I find a bit too close; after much experimentation I've come to ~ 2 picture heights. But this is a very personal preference.


----------



## erkq

millerwill said:


> My recommendation is to forget about SMPTE and THX and to decide for yourself. Sony recommends (for 4K) to sit up to 1.6 picture heights from the screen, but this I find a bit too close; after much experimentation I've come to ~ 2 picture heights. But this is a very personal preference.


Both SMPTE and THX give a range, not a single value. For a single value I agree, I doubt a strict 1.6 sh would satisfy very many. And it's ambiguous as well. Is it a 2.35 screen or a 16:9? At 1.6 sh I'd be sitting 8.5 feet back from my 10 foot wide screen. I wouldn't like that much either. It would be way off both SMPTE and THX recommendations as well... *far *too close.


----------



## darinp2

erkq said:


> Guys at trade shows aren't known to be fountains of technical knowledge.


For big companies I would agree that is often the case, although there are times I get to talk to people on the front lines of making decisions.

For very small companies where I get to talk to technical people I disagree with a basic question like I asked in this case. This was just after they had released a number for home. I haven't looked to see if they came up with new numbers since then, but even so it is important to know what their criteria was to come up with their number(s).


erkq said:


> Recommendations are given in degrees of viewing angle (what I assume you mean by viewing ratio).


Yep. They define each other.


erkq said:


> They are given as a range, not a single value. This governs where the frontmost and rearmost row can go for a given screen size. It's all very clearly presented and from your confused writing about your confusion I can only surmise you have never even looked at them. If you had, you would not be so confused.


Are you referring to something other than the 26 degree requirement and 36 degree recommendation from THX and if so, what are the specific numbers for 1080p and how did they determine them if you think they didn't determine a largest viewing angle for 1080p just the way they told me they came up with that number?

Do you know what those 26 and 36 degree numbers for commercial theaters meant? If so, what would you say they meant?

--Darin


----------



## millerwill

erkq said:


> Both SMPTE and THX give a range, not a single value. For a single value I agree, I doubt a strict 1.6 sh would satisfy very many. And it's ambiguous as well. Is it a 2.35 screen or a 16:9? At 1.6 sh I'd be sitting 8.5 feet back from my 10 foot wide screen. I wouldn't like that much either. It would be way off both SMPTE and THX recommendations as well... *far *too close.


As I said, I've iterated quite a bit before settling on my preferred location, which is with my eyes ~ 10.5 ft from 128"wide 16x9 pics and 144" wide 2.35 pics. (This a 72" high pic for 16x9 and 60" high for 2.35.)


----------



## darinp2

One more about this:


erkq said:


> THX and SMPTE are very explicit about how they arrive at their recommendations.


For 1080p displays does THX say whether their value came from a DLP, a regular LCD, an LCD with SmoothScreen, etc.? For the criteria of seeing pixel structures (what they told me) those would tend to be different and so would the visibility for artifacts, both from screen and from projectors. As far as seeing artifacts, would that be using some of the highest quality sources, or noisier sources. I wouldn't put DIRECTV 1080p content in the same category as 1080p Blu-ray for instance. Things like that matter to me if I am going to take someone else's opinion as applying to my situation and don't consider them having been "very explicit" if they aren't provide those kinds of details about how they arrived at their recommendations.

--Darin


----------



## bud16415

Until recently my thinking has been in the mind set like it has for the last decade that resolution and pixel size as some number of degrees of our cone of vision was one of the deciding factors and a key factor. In fact I started a thread about this last week and after a couple days of thinking about it and talking with some very bright and informed people here my thoughts suddenly became clear to me on the subject. I believe quite a few of the guidelines we took for the gospel are now up for interpretation. In looking at the data some groups have collected on where the threshold of being able identify a smaller resolution from a larger one are of course tied to the pixel size but that point is nowhere near the threshold of discerning and resolving a single pixel. In fact as close as I can figure the two are about 10X apart in terms of seating distance. Of course as Darin noted the technology DLP/LCD etc plays a role. If I had to guess 10X might be the number for DLP and 8X for LCD as both ends of the observation are lessened by the structure of the LCD pixel compared to the better DLP pixel. 

The days of testing when a body of people can see a pixel are over and really should have been over a long time ago. Pixel size on the other hand is important as it directly relates to these other qualities in our vision that basically can tell the difference between reality and a projected image and not identifying one pixel from the next. The old standard was based on the Snellen eye chart measurement of 1/60 of one degree of our vision being the pixel size when exceeded we could begin to see benefits of the next better resolution. That number was a bit arbitrary as tests have shown the real point is much smaller than that and when we can discern a pixel is greater than that. It is a great number for a 20/20 eye test black E on white paper but that’s about it IMO. Even if you only half believe the data or rather believe half the seating distance numbers reported. Both ends of the acuity range are outside any normal persons desired seating distance even the outliers are included. No one will ever desire sitting so close to 4k to be bothered by a pixel and never so far back to not see benefits even if very slight. 

What resolution for a given viewer is a different question and there will be many other improvements attached to UHD that 1080P most likely won’t get. 

Coming around to be on topic here. It is totally about personal choice and immersion and nothing else. Images are not to the point of realism but to a point of close enough. 

My closing thought is this I’m a Boston Celtics fan but interject you favorite team in its place. And going to a NBA game is not watching it on a projector it is something better than 8k as it is a real vision. But if you were given free tickets to a game and told you could sit in any seat you wanted to watch realism you would most likely pick half court first row. That would be like sitting 3 foot from a 160 “wrap-around screen. We would be moving our eyes head and body for a couple hours to take in the game and watch it and loving every second. Commercial theaters and their specs are to accommodate as many people as they can to maximize profits and they know the limits of enjoyable and I’m not paying good money to sit there. At home now there are no limits and really haven’t been for a long time with even 1080 and most people desires. Guidelines are great as a point of reference. Design your theater to best suit yourself and your family and friends and no reason to pack 500 people in your room.


----------



## jh901

anthonybuchanan said:


> Do they actually say my 130" diagonal 2.39 screen is NOT enjoyable at my preferred 6' to 7.5' viewing distance? Do they say that?


I don't know what "they" say, but I'd not be comfortable at 7.5' from a roughly 50" screen height. I'd be inclined to suggest that you are doing it wrong irrespective of your religious belief in the notion that 'personal preference' is all that matters. 'Personal preference' is flat out wrong most of the time. Curiosity is where it's at.


----------



## erkq

darinp2 said:


> One more about this:
> For 1080p displays does THX say whether their value came from a DLP, a regular LCD, an LCD with SmoothScreen, etc.? For the criteria of seeing pixel structures (what they told me) those would tend to be different and so would the visibility for artifacts, both from screen and from projectors. As far as seeing artifacts, would that be using some of the highest quality sources, or noisier sources. I wouldn't put DIRECTV 1080p content in the same category as 1080p Blu-ray for instance. Things like that matter to me if I am going to take someone else's opinion as applying to my situation and don't consider them having been "very explicit" if they aren't provide those kinds of details about how they arrived at their recommendations.
> 
> --Darin


I've been trying to find my references and I can't. I looked into this at a fairly deep level when I was designing my HT back in 2006. So I won't carry on in too much detail. But as I remember:

THX recommendations are based on ergonomic things like when does the feeling of immersion happen? When do you start having to move your head too much? How much brightness can the eye comfortably take in a dark room? How much light do you need to see details and color well? Where should the screen be placed vertically so you don't feel like you're craning your neck? SMPTE I remember even less of... just that it assumes the display type is film.

I never even thought about the fact THX doesn't bring display type into the equation. I just selected a 1080p projector that I liked and lost patience with all but the best Blu-ray and HD-DVD recordings. I don't watch any cable, TV, DVDs, or streaming. So, yeah... I have a large blind spot.

I *do *think Sony's 1.6 screen height is way out of *my *bounds. I know they're touting 4k, but it is no longer ergonomic, IMHO.


----------



## bud16415

erkq said:


> I *do *think Sony's 1.6 screen height is way out of *my *bounds. I know they're touting 4k, but it is no longer ergonomic, IMHO.


They don’t need to tout 4k by telling you that you can sit 1.6 SH away. It is reported you could begin to see the benefits of 4k over 1080p on a 100” screen from 60 feet away. 

If you want to sit 1.6 SH away that’s up to you. The image will look great that close just as it will from 2.5 SH away where a lot of people will sit. 

If someone wants to sit 1.6 SH I think its fine if they are recommending everyone do that then that’s crazy because some guy might want to sit 1.2 SH away and that’s cool too.


----------



## erkq

bud16415 said:


> ...
> 
> My closing thought is this I’m a Boston Celtics fan but interject you favorite team in its place. And going to a NBA game is not watching it on a projector it is something better than 8k as it is a real vision. But if you were given free tickets to a game and told you could sit in any seat you wanted to watch realism you would most likely pick half court first row. That would be like sitting 3 foot from a 160 “wrap-around screen. We would be moving our eyes head and body for a couple hours to take in the game and watch it and loving every second. Commercial theaters and their specs are to accommodate as many people as they can to maximize profits and they know the limits of enjoyable and I’m not paying good money to sit there. At home now there are no limits and really haven’t been for a long time with even 1080 and most people desires. Guidelines are great as a point of reference. Design your theater to best suit yourself and your family and friends and no reason to pack 500 people in your room.


Whew... I can't keep up. Anyway... this is an interesting idea. But at a BB game, each viewer has, in effect, a perfectly placed curved screen around just them where the their line of sight is always at a perfect 90 degrees to the screen. In a theater, the screen is flat, so the closer you sit, the more the image at the screen edges are elongated. In a BB game you follow the action up and down the "screen". In a theater, the program content may be designed for this kind of viewing, but most often is not.


----------



## bud16415

Yep you can’t do anything about that if you sit in the back row or the front row in real life you get a reality view of the world and a screen is or should be a window into a pure illusion of reality. Almost all of our vision both in real life and on screen is peripheral vision try and look at this X I just typed and without looking away from that X tell me what the word is 2 or 3 lines above or two or 3 words to the left or right. 

I actually agree with you I don’t have to sit close at all to the screen to become totally immersed in the content. Watch children watch a front projection movie they are interested in and have no idea how it works. See what they do and that’s the way we should all watch. 

Most of the displays we watched in life didn’t allow us to change size and then we get projection and it’s easy to be drawn in to going larger. Sometimes I think that’s what happens.


----------



## anthonybuchanan

erkq said:


> Both SMPTE and THX give a range, not a single value. For a single value I agree, I doubt a strict 1.6 sh would satisfy very many. And it's ambiguous as well. Is it a 2.35 screen or a 16:9? At 1.6 sh I'd be sitting 8.5 feet back from my 10 foot wide screen. I wouldn't like that much either. It would be way off both SMPTE and THX recommendations as well... *far *too close.


I seems to me you are just trying really hard to be able to say this standards body is correct.

Why doesn't someone ask Henderson how he came up with chart? 

He might say he threw darts on a wall.


----------



## anthonybuchanan

erkq said:


> EDIT: Wait... Darinp2? What gives? I thought I was responding to Anthony. You've been around *forever *and know *a lot*! How is this confusing?./QUOTE]
> 
> I've been around forever too.
> 
> I'm also a leader.
> 
> I am no follower just for the sake of being a follower. I follow only after I've investigated for myself.
> 
> For instance, Darin did all his CR research and shared it here. I thought, wow he has been around a long time but I want to see for myself if he is presenting something worth me implementing in my own HT or is it worth no more than the ink it would be on if printed.
> 
> I was prepared to dismiss it however it was very useful and I recommend anyone here reading it and implementing some of what he is saying. I think Darin is an awesome contributor here.
> 
> When I purchased my projector in 2010 I read a lot of comments to about the LG CF181D however I was not prepared to follow them until I tried it out side by side with 2 other projectors. I returned the other two.
> 
> You are a Follower right erkq?


----------



## erkq

anthonybuchanan said:


> I seems to me you are just trying really hard to be able to say this standards body is correct.
> 
> ...


Correct? No. As starting place? Yes. Personal preference is "correct". I believe I've posted as such many times.


----------



## darinp2

erkq said:


> THX recommendations are based on ergonomic things like when does the feeling of immersion happen? When do you start having to move your head too much? How much brightness can the eye comfortably take in a dark room? How much light do you need to see details and color well? Where should the screen be placed vertically so you don't feel like you're craning your neck?


I know they do take multiple things into account and do their best to make good recommendations. I admit that I haven't followed all of the posts in this thread, but just want to give a wrap-up of some points I wanted to get across:

- Shortly after THX released a closest viewing ratio for home for 1080p years ago they told me that the limiting factor for that number was seeing pixel structure. If a person ran that same test to see how close they could get before seeing pixel structure with their current display they could get a much different value.
- There has been much confusion at times about what the 26 degree requirement and 36 degree recommendation for THX in order to certify theaters meant. This was for worst case as far as viewers being too far away from the screen for commercial theaters with many seats. They were not recommending that people sit at a location where the viewing angle was 36 degrees, but that there not be a single seat in the theater where the viewing angle was less than 36 degrees, in which case most seats would result in higher angles.

I think the 26 and 36 values were easily misinterpreted and they could have probably been clearer long ago about what those meant.

It is always possible that people have understood what those meant for a while and I just missed the transition.

--Darin


----------



## erkq

anthonybuchanan said:


> I've been around forever too.
> ...


I see. I just haven't seen the input of, say, Darin.


anthonybuchanan said:


> I think Darin is an awesome contributor here.
> ...


Me too!



anthonybuchanan said:


> ...
> You are a Follower right erkq?


Hardly! I push the envelope. I love to talk about it. It's one of my passions! So you gave me an excuse! 

Dedicated space with projector room, AT screen, 8 AE-15 IB subs. (No need for butt-kickers!) 7 channels (soon to be 11) of hand built Dynaudio tri-amp'd speakers. yes, 22 amps and 7 electronic crossovers, parametric eq plus calibrating equipment. We are *trying* to love Game of Thrones, but my wife *is *completely in love with the cello in the theme music through these Dynaudios. An I1Pro 2 to profile a C6 with CalMAN, Lumagen and eeColor LUT boxes. The newest JVC projector. Honestly, do yourself a favor and check the JVCs out, though they are nowhere near perfect. (I'll PM you a list of their pro/con if you want.) But OMG, you should at least have a look! Even my wife is in love. She hit the roof when I bought it without her knowing (never try to surprise your wife with a big ticket item.) But now she's enthralled. Can hardly wait for UHD to get sorted so we can enjoy HDR, P3 color and (JVC's faux version of) 4k.

I really love this stuff and take any opportunity to share my journey. And these forums have been invaluable. I say, dig in and have fun!


----------



## erkq

darinp2 said:


> ...
> 
> I think the 26 and 36 values were easily misinterpreted and they could have probably been clearer long ago about what those meant.
> 
> It is always possible that people have understood what those meant for a while and I just missed the transition.
> 
> --Darin


Thanks Darin. I have understood this.


----------



## Gary Lightfoot

As Darin says (and I'm sure it was him who I first noted pointed this out many years ago and made me realise that was what it really meant), it's not unusual, even today, to see some online viewing distance calculators (including some very popular ones) say that 36 degrees is THXs recommended viewing angle. I've emailed a few of them to say that 36 is where they recommend the back row should be, not where you should sit, and given them a link to THXs website where it's documented with an image. One of them has added that note into the text prior to the calculator, but the calculator itself still says it's the recommended viewing angle. No wonder there is confusion about it.

The other viewing angles, such as their 'optimal'viewing angle, and very front row are not so well documented, but the info is out there. I think I've mentioned that already in previous posts.

Gary


----------



## anthonybuchanan

erkq said:


> I see. I just haven't seen the input of, say, Darin.
> 
> Me too!
> 
> 
> Hardly! I push the envelope. I love to talk about it. It's one of my passions! So you gave me an excuse!
> 
> Dedicated space with projector room, AT screen, 8 AE-15 IB subs. (No need for butt-kickers!) 7 channels (soon to be 11) of hand built Dynaudio tri-amp'd speakers. yes, 22 amps and 7 electronic crossovers, parametric eq plus calibrating equipment. We are *trying* to love Game of Thrones, but my wife *is *completely in love with the cello in the theme music through these Dynaudios. An I1Pro 2 to profile a C6 with CalMAN, Lumagen and eeColor LUT boxes. The newest JVC projector. Honestly, do yourself a favor and check the JVCs out, though they are nowhere near perfect. (I'll PM you a list of their pro/con if you want.) But OMG, you should at least have a look! Even my wife is in love. She hit the roof when I bought it without her knowing (never try to surprise your wife with a big ticket item.) But now she's enthralled. Can hardly wait for UHD to get sorted so we can enjoy HDR, P3 color and (JVC's faux version of) 4k.
> 
> I really love this stuff and take any opportunity to share my journey. And these forums have been invaluable. I say, dig in and have fun!


I hear you Brother. 

Thanks it's been fun.


----------



## Gary Lightfoot

anthonybuchanan said:


> I seems to me you are just trying really hard to be able to say this standards body is correct.
> 
> Why doesn't someone ask Henderson how he came up with chart?
> 
> He might say he threw darts on a wall.


According to Tom Holman of THX, they went back to some Kodak information dating back to the 50s, and just like Fox did before them, based it on image quality (visibility of film grain/sharpness, scratches, dirt etc, and projector mechanics) and immersion (closer is more immersive).

So it's research based on what you actually see in a real theatre, not on guesswork.

I'm guessing that with digital (1080) being cleaner (no projector mechanics issues except focus and tech differences, and tvs having different issues), and with film usually using a 2k DI, that the same recommendations still apply. THX did use to apply the caveat that it was with good quality source material on the website.

No darts involved.


----------



## anthonybuchanan

Gary Lightfoot said:


> According to Tom Holman of THX, they went back to some Kodak information dating back to the 50s, and just like Fox did before them, based it on image quality (visibility of film grain/sharpness, scratches, dirt etc, and projector mechanics) and immersion (closer is more immersive).
> 
> So it's research based on what you actually see in a real theatre, not on guesswork.
> 
> I'm guessing that with digital (1080) being cleaner (no projector mechanics issues except focus and tech differences, and tvs having different issues), and with film usually using a 2k DI, that the same recommendations still apply. THX did use to apply the caveat that it was with good quality source material on the website.
> 
> No darts involved.


Thanks. 

Was his name Henderson? 

Was he upset for not being able to go to the beach?


----------



## Gary Lightfoot

anthonybuchanan said:


> Thanks.
> 
> Was his name Henderson?
> 
> Was he upset for not being able to go to the beach?


I'm trying to help you out here, but you can't even read.

Added to my ignore list...


----------



## anthonybuchanan

Gary Lightfoot said:


> I'm trying to help you out here, but you can't even read.
> 
> Added to my ignore list...


No reason to get upset Gary. 

I made it clear I don't belive in the approach from the standpoint of what it is meant to solve and how it was derived. 

You can't "help you out" for someone that thinks it's all non useful information. I would bet a lot of money this organization has come up with some other stuff that I would fall in line with to the letter. Not this seating chart stuff though. 

I would like to be in a room with Henderson to discuss how he arrived at where he did.i iam certain I could convince him to see things my way. 

He would likely agree with me. However he would publish his seating chart anyway because as he would say,

"It's the one guideline we had not published before and they told me to do to add to our offerings". 

I beg of you to NOT ignore me just for this little thing. 

I will need you to "help me out" with something else later.


----------



## millerwill

bud16415 said:


> They don’t need to tout 4k by telling you that you can sit 1.6 SH away. It is reported you could begin to see the benefits of 4k over 1080p on a 100” screen from 60 feet away.
> 
> If you want to sit 1.6 SH away that’s up to you. The image will look great that close just as it will from 2.5 SH away where a lot of people will sit.
> 
> If someone wants to sit 1.6 SH I think its fine if they are recommending everyone do that then that’s crazy because some guy might want to sit 1.2 SH away and that’s cool too.


I agree that 1.6 SH is a bit too close for my taste; I have settled on ~ 2.0 SH (1.8 for 16x9, and 2.2 for 2.35 pics--i.e., ~ 11 ft from a 6ft H 16x9 pic and 5ft H pic for 2.35). 

I find this to be very immersive but not overwhelming and tiresome.


----------



## nathan_h

I'm a fan of 2 heights from a 2.35:1 screen.


----------



## erkq

nathan_h said:


> I'm a fan of 2 heights from a 2.35:1 screen.


Yup... I'm right about there too. That would be 11' from my screen. My front row is at 10' and that's where I watch 2.35 from.


----------



## rastuso

Older thread, but I was looking this up again, after a Facebook conversation.

In my low budget, high WAF theater, I sit about 8 feet from my 100" diagonal projected 1080p image. I think it's perfect. THX would tell you I should be 3 or 4 feet further back, which imho is CRAZY! Maybe there is a reason why there are now only a couple dozen THX commercial theaters left.

THe low viewing angle goes in absolute stark contrast to IMAX, which is supposed to be the ultimate viewing experience, right? Even the LieMAXs To meet the THX recommended viewing angle in a LieMAX theater, or the bigger screens in a modern multiplex, you'd be near the back row (hell, maybe back in the projection room), and of course then WAY too high. NO ONE who has a home theater would choose that. We're going to choose the 3rd or fourth row up from the wheelchair level that puts our eyes 1/3 of the way up the screen, with a very large viewing angle.

Why on Earth would I choose a much tighter one, perhaps half of that, at home? Yeah, if I stare at a static image on my screen, I can see pixels. But guess what, once Deadpool starts counting down bullets, I'm sure not seeing pixels. 

I do this: Go to your favorite theater, sit in your favorite seat, and take a real close look at how the screen looks. If you wear glasses, they are a GREAT frame. See where the screen lies in respect to your frames. Most likely it fills them. Now go home, and sit at the THX distance from your screen. It won't even be close to filling up your frames.

THat brings me back to why I'm here. I saw yet another person bragging about a home theater on FB that has the seats ridiculously far from the screen, and too high. People will drop tens of thousands of dollars on a theater, and have a very sub par experience to the local Regal, and wonder what went wrong.

I really should design home theaters for a living. So many people get taken by dumbasses who have no idea what they're doing.

Jason


----------



## Gary Lightfoot

You're sitting at roughly 2x screen height which is SMPTEs closest recommended, but that's about where I like to sit, albeit with a 2.35 screen rather than 16:9. For the aspect changing movies like TDK I'm at around 1.5xSH which is more like IMAX than normal cinema. I'm running a 2.35+IMAX set up rather than plain 16:9 which shows 2.35 movies smaller than 16:9 (wrong way round).

IMAX is very different to normal movies, and movies are shot differently to cater for it - the horizon line is very low and below center to prevent people looking up and getting neck ache due to the much closer seating distances and raked stadium seating arrangement. Normal SMPTE/THX recommendations are not designed for IMAX and that's why they don't apply there.

Don't give up your day job.

Gary


----------



## rastuso

People who really want that top end experience sit closer. My whole point is people going to say they want a THX like room in their house, and they'll end up with seats 1.75 times the width from their screen, which is ridiculously far. Even when I see celebrity home theaters, I just laugh. ANd you know those cost at least 50 grand, then another 30 grand in sound equipment. ANd then a screen so small it's laughable.

I'm always amazed at the fact that almost all of them have the screens way too high. But, we live in a world where above the fireplace has become the position of choice, which is beyond dumb.

http://4rilla.blogspot.com/2009/01/pictures-of-gary-dellabates-home.html

https://www.pinterest.com/pin/103653228896788264/

https://www.pinterest.com/pin/103653228896788222/

https://www.pinterest.com/pin/103653228896788105/

https://www.pinterest.com/pin/103653228896788068/

WOW, had to add this one:
https://www.pinterest.com/pin/103653228896788078/

And these were NOT cheap theaters, but don't even come close to delivering the experience they should.

Jason


----------



## Gary Lightfoot

I don't disagree.

I think the main problem is they don't come to avs...

Gary


----------



## millerwill

rastuso said:


> Older thread, but I was looking this up again, after a Facebook conversation.
> 
> In my low budget, high WAF theater, I sit about 8 feet from my 100" diagonal projected 1080p image. I think it's perfect. THX would tell you I should be 3 or 4 feet further back, which imho is CRAZY! Maybe there is a reason why there are now only a couple dozen THX commercial theaters left.
> 
> THe low viewing angle goes in absolute stark contrast to IMAX, which is supposed to be the ultimate viewing experience, right? Even the LieMAXs To meet the THX recommended viewing angle in a LieMAX theater, or the bigger screens in a modern multiplex, you'd be near the back row (hell, maybe back in the projection room), and of course then WAY too high. NO ONE who has a home theater would choose that. We're going to choose the 3rd or fourth row up from the wheelchair level that puts our eyes 1/3 of the way up the screen, with a very large viewing angle.
> 
> Why on Earth would I choose a much tighter one, perhaps half of that, at home? Yeah, if I stare at a static image on my screen, I can see pixels. But guess what, once Deadpool starts counting down bullets, I'm sure not seeing pixels.
> 
> I do this: Go to your favorite theater, sit in your favorite seat, and take a real close look at how the screen looks. If you wear glasses, they are a GREAT frame. See where the screen lies in respect to your frames. Most likely it fills them. Now go home, and sit at the THX distance from your screen. It won't even be close to filling up your frames.
> 
> THat brings me back to why I'm here. I saw yet another person bragging about a home theater on FB that has the seats ridiculously far from the screen, and too high. People will drop tens of thousands of dollars on a theater, and have a very sub par experience to the local Regal, and wonder what went wrong.
> 
> I really should design home theaters for a living. So many people get taken by dumbasses who have no idea what they're doing.
> 
> Jason


I'm in complete agreement with you; I sit ~ 11 ft from a 6 ft H 16x9 screen. It is this immersive experience that is the most important aspect of HT, at least for me.


----------



## rastuso

millerwill said:


> I'm in complete agreement with you; I sit ~ 11 ft from a 6 ft H 16x9 screen. It is this immersive experience that is the most important aspect of HT, at least for me.


6 feet high! Damn, that's nice. I'm low budget, so it's a 4x8 painted piece of Masonite
.

Jason


----------



## millerwill

rastuso said:


> 6 feet high! Damn, that's nice. I'm low budget, so it's a 4x8 painted piece of Masonite
> .
> 
> Jason


Well, you've got something to look forward to when you're further along! (I just turned 75.) Only a few yrs ago did I go as large as my room can take, a 6ft H x 12ft W screen (6ft H for 16x9 pics, and 12ft W for 2.35), and size really does matter.


----------



## erkq

rastuso said:


> Older thread, but I was looking this up again, after a Facebook conversation.
> 
> In my low budget, high WAF theater, I sit about 8 feet from my 100" diagonal projected 1080p image. I think it's perfect. THX would tell you I should be 3 or 4 feet further back, which imho is CRAZY! Maybe there is a reason why there are now only a couple dozen THX commercial theaters left.
> 
> THe low viewing angle goes in absolute stark contrast to IMAX, which is supposed to be the ultimate viewing experience, right? Even the LieMAXs To meet the THX recommended viewing angle in a LieMAX theater, or the bigger screens in a modern multiplex, you'd be near the back row (hell, maybe back in the projection room), and of course then WAY too high. NO ONE who has a home theater would choose that. We're going to choose the 3rd or fourth row up from the wheelchair level that puts our eyes 1/3 of the way up the screen, with a very large viewing angle.
> 
> Why on Earth would I choose a much tighter one, perhaps half of that, at home? Yeah, if I stare at a static image on my screen, I can see pixels. But guess what, once Deadpool starts counting down bullets, I'm sure not seeing pixels.
> 
> I do this: Go to your favorite theater, sit in your favorite seat, and take a real close look at how the screen looks. If you wear glasses, they are a GREAT frame. See where the screen lies in respect to your frames. Most likely it fills them. Now go home, and sit at the THX distance from your screen. It won't even be close to filling up your frames.
> 
> THat brings me back to why I'm here. I saw yet another person bragging about a home theater on FB that has the seats ridiculously far from the screen, and too high. People will drop tens of thousands of dollars on a theater, and have a very sub par experience to the local Regal, and wonder what went wrong.
> 
> I really should design home theaters for a living. So many people get taken by dumbasses who have no idea what they're doing.
> 
> Jason


Before you sling "dumbass" labels around so freely, perhaps you should read what those THX specs actually are. They are the minimum angle of view. *That *is the reason you'd be in the back row in a commercial theater. That is exactly right. I sit 10' back from my 10' wide screen (145" diagonal). So as it turns out I think we're pretty much in agreement as to where to sit.


----------



## rboster

I thought this was an interesting poll

http://www.avsforum.com/forum/92-co...-viewing-distance-relative-screen-height.html


----------



## contactjustind

All the images in the first post are broken. Does anyone have them?


----------



## anthonybuchanan

erkq said:


> Before you sling "dumbass" labels around so freely, perhaps you should read what those THX specs actually are. They are the minimum angle of view. *That *is the reason you'd be in the back row in a commercial theater. That is exactly right. I sit 10' back from my 10' wide screen (145" diagonal). So as it turns out I think we're pretty much in agreement as to where to sit.


The guidelines telling you to sit close are worthless. I would imagine they came about with something like the interaction below between an employee and his boss where the boss wants to round out their portfolio of white papers with something dictating to people where they should sit. 

Boss: "Hey Hendersen what are you working on today".
Hendersen: "I just finished the project you had me working on".
Boss: "What are you working on next?"
Hendersen: "My week is clear I don't have any other projects I was thinking of going to the beach".
Boss: "What? You're going to the beach?"
Boss: "Makeup some damn white paper and tell people where to sit in their HT".
Boss: "And put our seal on it to make it real official like".
Hendersen: "Okay boss I will just publish some crap".


----------



## erkq

anthonybuchanan said:


> The guidelines telling you to sit close are worthless. I would imagine they came about with something like the interaction below between an employee and his boss where the boss wants to round out their portfolio of white papers with something dictating to people where they should sit.
> 
> Boss: "Hey Hendersen what are you working on today".
> Hendersen: "I just finished the project you had me working on".
> Boss: "What are you working on next?"
> Hendersen: "My week is clear I don't have any other projects I was thinking of going to the beach".
> Boss: "What? You're going to the beach?"
> Boss: "Makeup some damn white paper and tell people where to sit in their HT".
> Boss: "And put our seal on it to make it real official like".
> Hendersen: "Okay boss I will just publish some crap".


If you want to make your point by making stuff up, you can. But I have no response to it.


----------



## anthonybuchanan

erkq said:


> If you want to make your point by making stuff up, you can. But I have no response to it.



You cannot prove what I said resulted in the worthless guideline is wrong.


----------



## erkq

anthonybuchanan said:


> You cannot prove what I said resulted in the worthless guideline is wrong.


Asking someone to prove a negative is an age-old logical trick and I'm not falling for it. Prove to me that the Cookie Monster doesn't exist.


----------



## anthonybuchanan

erkq said:


> Asking someone to prove a negative is an age-old logical trick and I'm not falling for it. Prove to me that the Cookie Monster doesn't exist.


I believe the Cookie Monster does exist so I cannot prove he doesn't exist.


----------



## erkq

anthonybuchanan said:


> I believe the Cookie Monster does exist so I cannot prove he doesn't exist.


Har...


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## rboster

erkq said:


> If you want to make your point by making stuff up, you can. But I have no response to it.


Didn't you know we are now in the world of alternative facts. Colbert perdicted this new fact free world years ago when he created the word "truthiness"

truth·i·ness
the quality of seeming or being felt to be true

Whenever he lacks an coherent set of facts to debate the topic, he types this fake exchange. The fake exchange is based on what he would like to have happened to support his position.


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## erkq

rboster said:


> Didn't you know we are now in the world of alternative facts. Colbert perdicted this new fact free world years ago when he created the word "truthiness"
> 
> truth·i·ness
> the quality of seeming or being felt to be true
> 
> Whenever he lacks an coherent set of facts to debate the topic, he types this fake exchange. The fake exchange is based on what he would like to have happened to support his position.


Yes... very familiar with it. Colbert is genius. Truthiness has become part of the lexicon.


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## anthonybuchanan

rboster said:


> Didn't you know we are now in the world of alternative facts. Colbert perdicted this new fact free world years ago when he created the word "truthiness"
> 
> truth·i·ness
> the quality of seeming or being felt to be true
> 
> Whenever he lacks an coherent set of facts to debate the topic, he types this fake exchange. The fake exchange is based on what he would like to have happened to support his position.


I need your help in deciding if something is a "Fact", an "Alternative Fact" or simply "Trustiness" 

Below is the exact workplace exchange that resulted in the "sit close" guideline. I know it to be true become I heard people are saying it. 

Boss: "Hey Hendersen what are you working on today".
Hendersen: "I just finished the project you had me working on".
Boss: "What are you working on next?"
Hendersen: "My week is clear I don't have any other projects I was thinking of going to the beach".
Boss: "What? You're going to the beach?"
Boss: "Makeup some damn white paper and tell people where to sit in their HT".
Boss: "And put our seal on it to make it real official like".
Hendersen: "Okay boss I will just publish some crap".

Is it" Fact", "Alternative Fact" or "Trustiness"? 

Please help.


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## erkq

anthonybuchanan said:


> I need your help in deciding if something is a "Fact", an "Alternative Fact" or simply "Trustiness"
> 
> Below is the exact workplace exchange that resulted in the "sit close" guideline. I know it to be true become I heard people are saying it.
> 
> Boss: "Hey Hendersen what are you working on today".
> Hendersen: "I just finished the project you had me working on".
> Boss: "What are you working on next?"
> Hendersen: "My week is clear I don't have any other projects I was thinking of going to the beach".
> Boss: "What? You're going to the beach?"
> Boss: "Makeup some damn white paper and tell people where to sit in their HT".
> Boss: "And put our seal on it to make it real official like".
> Hendersen: "Okay boss I will just publish some crap".
> 
> Is it" Fact", "Alternative Fact" or "Trustiness"?
> 
> Please help.


I've not heard of "Trustiness" so I'm not sure how to respond.


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## anthonybuchanan

Oops. 
It's the autocorrect. 
Sucks. 
I'm embarrassed.


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## erkq

anthonybuchanan said:


> Oops.
> It's the autocorrect.
> Sucks.
> I'm embarrassed.


Well, then I think that would be "truthiness".


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## rboster

anthonybuchanan said:


> Oops.
> It's the autocorrect.
> Sucks.
> I'm embarrassed.


No worries....autocorrect can be blessing or a curse. That reminds me how much I miss the colbert report.


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## bud16415

contactjustind said:


> All the images in the first post are broken. Does anyone have them?


The information was on a user’s imageshack acct and the photos were lost it seems. They came from the carltonbale site originally. He has the widely used “where resolution becomes noticeable” graph. That graph and the viewing seating graph are both located on the same page and you can view them there. http://carltonbale.com/1080p-does-matter/

That information for me has always been confusing and in some people misleading IMO. I started a thread once investigating all this and drew my own personal conclusions about this and started a somewhat controversial thread where I came up with some alternate graphs I felt were more meaningful and I compiled all my findings into the first post. The grinding out the debate is in the body of the thread for all to read. 

Those charts can be found here. http://www.avsforum.com/forum/68-di...ting-distance-720-1080-uhd-visual-acuity.html

Look over my thread and the first link and draw your own conclusions.


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## Dave in Green

Visual acuity studies and silly interpretations aside, screen size and viewing distance are purely personal preferences that are best determined by each individual conducting their own experimentation. You can start from the THX and SMPTE recommendations if you want, but you should never let them limit your freedom of choice.


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## bud16415

Dave in Green said:


> Visual acuity studies and silly interpretations aside, screen size and viewing distance are purely personal preferences that are best determined by each individual conducting their own experimentation. You can start from the THX and SMPTE recommendations if you want, but you should never let them limit your freedom of choice.


You left one out. 
Screen size, Viewing distance and (*Projector Resolution*).


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## Dave in Green

I didn't leave it out. It wasn't relevant to my main point, which is that people differ in their preference for screen size and viewing distance (with any projector resolution).


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## bud16415

Dave in Green said:


> I didn't leave it out. It wasn't relevant to my main point, which is that people differ in their preference for screen size and viewing distance (with any projector resolution).


For many years screen (size > viewing distance = immersion) was limited by silly acuity interpretations The size of the pixel forced the change in perception of reality in the image even when a single pixel couldn’t be discerned. That’s why ten year ago a screen size of 100” was considered large. For the most part during the time period between then and now houses didn’t get a lot larger rooms are about the same size and the number of people viewing in a home theater haven’t increased. Resolution and picture quality has improved both at home and tremendously in commercial theaters transitioning over to HD digital. Some older viewers are evolving their level of immersion and new viewers are selecting their level of immersion. Of course it is personal I have a whole thread in the CIH forum suggesting an alternate to CIH being PIA personal image area, where I suggest presentation / immersion is an individual thing and does not have to be a constant in our home theaters. Each time we go to the theater we have many rows to pick from at home most are forced into a fixed distance to the screen and the people doing CIW are really hurting themselves when watching scope movies 2.35:1. The size that is supposed to eclipse all but Imax. In suggesting this personal choice over there because now modern projectors allow it, The most scholarly of us at AVS reject this idea stating the old standards of SMPTE and THX are the word and built around human studies, and the sweet spot is the sweet spot. And when you find yours it is no longer a variable. 

There is another side to the change in immersion that isn’t directly related to learned behavior. As flat panel screens grew to the size they are now and as resolution and PQ improved people were drawn in by slightly more immersion and at the same time they wanted projection to still eclipse TV. I still don’t know many that sit 3 foot from a 60” UHD TV. 

An interesting note is if you look at the design of the circa 1920-30 movie palace you will find people were sitting in crazy immersive seats. SMPTE later came along and with the advent of all the scope like AR’s and changed that. 

So I disagree play the same movie in VGA and UHD4k resolutions for a test audience and ask them to sit where they like. You won’t find too many sitting 1.5-2.0 X screen height away from the VGA image. You will find them liking and enjoying that image at 6.0 X though. 

If you are a classic film buff like I am or someone that enjoys classic TV. Many of these things have been remastered and many not. If you are a person that might like to watch a movie like Avatar as if in an Imax theater but a romantic comedy as an easy watch. Then all these standards go out the window on a practical level as well as a visual acuity level, and PIA is what you should be thinking about.


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## micky_macca

Hey guys, long time lurker first time poster 

I recently picked up a non working Epson 8350 (US model, I live in Australia) projector for $50, long story short it was a little servo motor and I have ordered a replacement part for $5 off ebay so that is all sorted now.

Now my plan was to get the projector all sorted then throw it up on the wall and see what size screen looked good etc etc.

Anyway I have impulse bought a screen technics 92" fixed screen from a guy nearby off gumtree, I picked it up for $150 and it is in perfect condition so I though it was too good to pass up.

Now the details are:

View distance from screen: 2.95M

Maximum throw distance from projector lense to screen: 2.8M

Now I have done a bit of a calculation on projector central and to me it appears that if I put a 2.8M throw distance in it gives me a max diagonal screen size of 69" (I will talk in imperial regarding screen size as it is easier to relate in my opinion) however this I believe is right in the middle of the possible zoom ratio's? Would I be correct in assuming that? If I look at the throw range in the top right it appears if I zoom out I could get to a relative 4.38M?

If I am correct in my thinking and type a 4.38M throw distance in it shows a 100"+ screen size.

So am I reading all this correctly? I am a projector newbie so this is all foreign.

Also any opinions on full 1080p content from 3m away?

I would only watch 1080p content, no lower quality source material.

Thanks for any input guys


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## Gary Lightfoot

Using this calculator (assuming it's the same 8350):

http://www.projectorcentral.com/Epson-PowerLite_Home_Cinema_8350-projection-calculator-pro.htm

It looks like you can get (43" to) 93 diag from 2.8m

From 4.3m you can get 6" to 145"

2.95m from a 92" diagonal 16:9 screen (1.2m tall) is just fine (approx 2.5 x screen height).


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## ellisr63

We watched our 15' wide scope screen from 12', and loved it. Most of our guests also preferred sitting close too. The only ones that preferred the 2nd row were the ones that preferred the height of the 2nd row, and if the 1st row had been raised up (like our 2nd row was for our DTS10 sub) they would have preferred the 12' distance over the 2nd row seating.

Sent from my SM-T550 using Tapatalk


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## Erod

The sweet spot for viewing is between 42 to 50 degrees.

Unless you like to watch tennis matches and have your head on a swivel the whole time. 

To each his own obviously. I like it around 44-45 degrees.


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## Technology3456

Two quick questions. 1. What % dimmer do the sides of a screen have to be than the center before it is noticeable in real content? 2. Does the % change in 2D vs 3D? 

I am trying to decide on a high gain screen but the higher the gain, the more hotspotting, so I am trying to figure out what the "allowable tolerance" is for brightness dropoff on the sides before it becomes noticeable in content, and then based on that I can determine how high gain I can go.


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## bud16415

Technology3456 said:


> Two quick questions. 1. What % dimmer do the sides of a screen have to be than the center before it is noticeable in real content? 2. Does the % change in 2D vs 3D?
> 
> I am trying to decide on a high gain screen but the higher the gain, the more hotspotting, so I am trying to figure out what the "allowable tolerance" is for brightness dropoff on the sides before it becomes noticeable in content, and then based on that I can determine how high gain I can go.


I have always been told that most people can't detect a half f-stop change from center to side with a fully immersive image.


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## Technology3456

bud16415 said:


> I have always been told that most people can't detect a half f-stop change from center to side with a fully immersive image.


Thanks for responding. I am not familiar with photography, could you please explain how much a half f-stop is? If the center is 1,000 lumens, and there is a half f-stop change from center to the side, then how many lumens is the side?


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## bud16415

Technology3456 said:


> Thanks for responding. I am not familiar with photography, could you please explain how much a half f-stop is? If the center is 1,000 lumens, and there is a half f-stop change from center to the side, then how many lumens is the side?


f-stops and shutter speed go back to the days of manual film cameras and worked hand in hand. Each shutter speed going faster was half the time setting and each f-stop doubled the light.

So in terms of projectors a full f-stop reduction going from 1000 would be reduced by half and be 500. A half f-stop would be reduced by 250 and result in 750 lumens.

Actually the reason this works is our eyes have the ability to adjust somewhere around 22 f-stops so picture a progression like 1-2-4-8-16-32-64-128….. 22 times and you will realize just how amazing our eyes are. When you are somewhere in the central part of the eyes range a change in overall image wont be noticed of a full f-stop in a full image taken in by the eye. I remember many times taking photos with a manual camera being outside and having the exposure set for a photo and taking another a few minutes later. My eyes and brain told me nothing had changed in the brightness outside but the camera says I need to open the lens 2 f-stops. The reason it looked the same to the eye is my iris in my eyes had already compensated the 2 f-stops to keep the image I see constant.

This same thing happens when you scan across a projection screen searching out detail in the image to compare brightness. Your eyes don’t let you know that the level has changed when within certain limits.

Years ago there was much more talk about warm spotting and hot spotting and where the lens height was related to eyes and if the screen was flat or curved or curved in two directions or one and of course the gain of the screen. As projectors got brighter with better CR screens were able to become simpler, and this topic became less. Then the ALR craze started as folks feel they want projection in rooms with lights on.
Really IMO 1.2 –1.3 gain away from a 1.0 lambertian reflectance is the point there becomes noticeable compromises in screen performance. Some are very slight and some become more apparent the more off axis you sit. Sometimes the trade off is acceptable as you just need the extra brightness or ALR properties. It is very hard to beat a 1.0-1.2 gain white screen in a perfect room given a bright enough projector. HDR has kind of threw a wrench into the gears IMO as people feel the HDR brightness is important and are shooting for higher numbers than they used to. That’s another topic though.


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## Technology3456

bud16415 said:


> f-stops and shutter speed go back to the days of manual film cameras and worked hand in hand. Each shutter speed going faster was half the time setting and each f-stop doubled the light.
> 
> So in terms of projectors a full f-stop reduction going from 1000 would be reduced by half and be 500. A half f-stop would be reduced by 250 and result in 750 lumens.
> 
> Actually the reason this works is our eyes have the ability to adjust somewhere around 22 f-stops so picture a progression like 1-2-4-8-16-32-64-128….. 22 times and you will realize just how amazing our eyes are. When you are somewhere in the central part of the eyes range a change in overall image wont be noticed of a full f-stop in a full image taken in by the eye. I remember many times taking photos with a manual camera being outside and having the exposure set for a photo and taking another a few minutes later. My eyes and brain told me nothing had changed in the brightness outside but the camera says I need to open the lens 2 f-stops. The reason it looked the same to the eye is my iris in my eyes had already compensated the 2 f-stops to keep the image I see constant.
> 
> This same thing happens when you scan across a projection screen searching out detail in the image to compare brightness. Your eyes don’t let you know that the level has changed when within certain limits.
> 
> Years ago there was much more talk about warm spotting and hot spotting and where the lens height was related to eyes and if the screen was flat or curved or curved in two directions or one and of course the gain of the screen. As projectors got brighter with better CR screens were able to become simpler, and this topic became less. Then the ALR craze started as folks feel they want projection in rooms with lights on.
> Really IMO 1.2 –1.3 gain away from a 1.0 lambertian reflectance is the point there becomes noticeable compromises in screen performance. Some are very slight and some become more apparent the more off axis you sit. Sometimes the trade off is acceptable as you just need the extra brightness or ALR properties. It is very hard to beat a 1.0-1.2 gain white screen in a perfect room given a bright enough projector. HDR has kind of threw a wrench into the gears IMO as people feel the HDR brightness is important and are shooting for higher numbers than they used to. That’s another topic though.


Thanks for explaining, great info. I would need the high gain for 3D double stack where the filters are taking 50% - 90% of the brightness away otherwise I would go with 1.0 screen. The high gain screen Im estimating has 40 degree half gain angle. We're talking like a 3 gain screen here so way above 1.3. Based on my calculations at my distance and screen size, for the center seat, if center screen is 1,000 lumens, the sides will be just under 800. So it falls within the allowable tolerance in your post. But for seats to the left and right of center seat, it might be 1,000 in the middle, and better than 800 on one side, but maybe 650 on the far side. So a drop from 1,000 to 650. That has to be noticeable right, or no?


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## bud16415

Technology3456 said:


> Thanks for explaining, great info. I would need the high gain for 3D double stack where the filters are taking 50% - 90% of the brightness away otherwise I would go with 1.0 screen. The high gain screen Im estimating has 40 degree half gain angle. We're talking like a 3 gain screen here so way above 1.3. Based on my calculations at my distance and screen size, for the center seat, if center screen is 1,000 lumens, the sides will be just under 800. So it falls within the allowable tolerance in your post. But for seats to the left and right of center seat, it might be 1,000 in the middle, and better than 800 on one side, but maybe 650 on the far side. So a drop from 1,000 to 650. That has to be noticeable right, or no?


As long as it is gradual I think 650 in good room without a lot of competing light would be ok as long as the screen size was within range. You should really talk FL foot lamberts when talking how our vision reacts to changing brightness. Right in the center of our comfort range IMO we are more forgiving of drop off.
When I was watching 3D I was planning a different screen that I could pull down. I never got around to it though.


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## Technology3456

bud16415 said:


> As long as it is gradual I think 650 in good room without a lot of competing light would be ok as long as the screen size was within range. You should really talk FL foot lamberts when talking how our vision reacts to changing brightness. Right in the center of our comfort range IMO we are more forgiving of drop off.
> When I was watching 3D I was planning a different screen that I could pull down. I never got around to it though.


Well your post brings up a good question. Before your post, I was just trying to find out, what is the best foot lamberts to aim for for 3D? After your post, I realize I can't answer your question about how many ftl are in the center and how many are on the side without knowing, whatever the best number for 3D is, do I want that number in the center, and less on the sides? Or do I want more in the center so I can have the correct number on the sides?

Say 15 ftl is ideal for 3D. That means I could either have 15ftl in the middle, and 11 - 12 ftl on the sides, or I could have almost 20ftl in the middle, and 15ftl on the sides. I think more is better unless 20ftl would be too bright in 3D, which most people would laugh at but I was advised if you go too bright with passive 3D, as opposed to 2D, it can start to make the crosstalk more visible because it's brighter. 

But to answer your question, I'd say for the center seat, 20 foot lamberts center screen, and 15 to 16 on the sides. For seats to the left and right, 19 foot lamberts center screen, 17 foot lamberts on the side the seat is on, and 13 foot lamberts to the far side. So dropping from 19 to 13, let's say, at the worst case. Is that too much to be advisable?


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## bud16415

Technology3456 said:


> Well your post brings up a good question. Before your post, I was just trying to find out, what is the best foot lamberts to aim for for 3D? After your post, I realize I can't answer your question about how many ftl are in the center and how many are on the side without knowing, whatever the best number for 3D is, do I want that number in the center, and less on the sides? Or do I want more in the center so I can have the correct number on the sides?
> 
> Say 15 ftl is ideal for 3D. That means I could either have 15ftl in the middle, and 11 - 12 ftl on the sides, or I could have almost 20ftl in the middle, and 15ftl on the sides. I think more is better unless 20ftl would be too bright in 3D, which most people would laugh at but I was advised if you go too bright with passive 3D, as opposed to 2D, it can start to make the crosstalk more visible because it's brighter.
> 
> But to answer your question, I'd say for the center seat, 20 foot lamberts center screen, and 15 to 16 on the sides. For seats to the left and right, 19 foot lamberts center screen, 17 foot lamberts on the side the seat is on, and 13 foot lamberts to the far side. So dropping from 19 to 13, let's say, at the worst case. Is that too much to be advisable?


Too much is better than not enough. You can always cut it back easier than trying to add brightness to the projector. Also lamps dim with age and i always set mine up to be able to adjust brightness back over time.


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