Wall color for HT

[Mingus]

My neighbor is renovating their basement and setting up a HT. The question is, what is the best color for the wall where the screen is located. I've read someplace that the color should be a neutral tone - like gray. His wife prefers lilac (a feng shui color) to match the decor. Does the color of the other walls make a difference.

[Sir Terrence the Terrible]

My neighbor is renovating their basement and setting up a HT. The question is, what is the best color for the wall where the screen is located. I've read someplace that the color should be a neutral tone - like gray. His wife prefers lilac (a feng shui color) to match the decor. Does the color of the other walls make a difference.

The proper shade for the front wall should be black. His wife should really stay out of this one, as she is trying to be decorative when in reality this should be more for performance and function. To enhance contrast the front wall should always be black. Using black assures that whatever light that bounces back from the side and rear walls will be absorbed, which enhances the contrast profoundly.

[pixelthis]

THE BOOK says 6500k, for everything in the room.
Believe it or no, but everything affects your picture, even your clothes, although not much.
So black would be decent as a background for the screen, but if you're not the morbid type,
any dark color will do, really.:1:

[Mingus]

Thanks for the infos. They settled on chocalate brown, a dark color - the lilac is out. I learn from the past that Feng Shui principles and HT applications don't mix well. What about the other three walls. Does it have any bearing on the picture.

[Sir Terrence the Terrible]

THE BOOK says 6500k, for everything in the room.
Believe it or no, but everything affects your picture, even your clothes, although not much.
So black would be decent as a background for the screen, but if you're not the morbid type,
any dark color will do, really.:1:

There is no book that says 6500k everywhere pix jeeze louise!!!!

Bias lights are used for folks who sit far away from their sets(which are usually 40" and under) - far enough away that the set does not take up your field of view. In this case when watching your set with the lights off, your eyes have to adjust quickly for the changing light on the screen. This can cause eye fatigue. A bias light is used to provide a bit of light to keep the pupils more open(thereby reducing eyestrain), and not forcing them to make rapid changes scene by scene. The light should be placed low and behind the set, and should have a color temperature of 6500k.

This does not apply to the people who sit the proper distance for HD, or to those folks who have projection systems. The screens are so big that it takes up your field of view(which also gives out more light to the eyes), which keeps the pupil open most of the time thereby preventing eye strain.

[Sir Terrence the Terrible]

Thanks for the infos. They settled on chocalate brown, a dark color - the lilac is out. I learn from the past that Feng Shui principles and HT applications don't mix well. What about the other three walls. Does it have any bearing on the picture.

Chocolate brown is perfectly acceptable. The other three walls should also be dark as well, so as not to reflect light back to the screen which also reduces contrast. Ideally, the whole room should be dark for just that reason.

[Geoffcin]

In addition all paint should be flat, or preferably even matte. Reflections off even a dark but shiny surface can cause distractions.

[pixelthis]

There is no book that says 6500k everywhere pix jeeze louise!!!!

Bias lights are used for folks who sit far away from their sets(which are usually 40" and under) - far enough away that the set does not take up your field of view. In this case when watching your set with the lights off, your eyes have to adjust quickly for the changing light on the screen. This can cause eye fatigue. A bias light is used to provide a bit of light to keep the pupils more open(thereby reducing eyestrain), and not forcing them to make rapid changes scene by scene. The light should be placed low and behind the set, and should have a color temperature of 6500k.

This does not apply to the people who sit the proper distance for HD, or to those folks who have projection systems. The screens are so big that it takes up your field of view(which also gives out more light to the eyes), which keeps the pupil open most of the time thereby preventing eye strain.

Its called a BACKLIGHT, what I HAVE BEEN SAYING that you need and you have been saying you don't need, my reasons for saying you need it the same as the reasons you cited above, doesnt matter if you have a projection, direct view,
or PUPPET THEATER.
6500K (the proper temp for video pictures) is the ideal type of paint for HT, they sell it
and while it might not go with the decor, it has several advantages.:1:

[Sir Terrence the Terrible]

Its called a BACKLIGHT, what I HAVE BEEN SAYING that you need and you have been saying you don't need, my reasons for saying you need it the same as the reasons you cited above, doesnt matter if you have a projection, direct view,
or PUPPET THEATER.
6500K (the proper temp for video pictures) is the ideal type of paint for HT, they sell it
and while it might not go with the decor, it has several advantages.:1:

Pix, you have a smaller display than my smallest display, and you don't sit the proper distance from the television (1.5 heights away for HD content), so you need a backlight. My smallest television is 55", and I sit exactly 1.5 screen heights away. You don't need a back light with this set up. When you sit too far away in a dark room(the proper way to watch movies), and you have a bright source constantly changing light levels in darkness, that is the problem as it makes the pupils rapidly have to adjust to the changing light levels. When you sit closer, there is more light hitting the pupils, which allows them to stay more open, and not have to rapidly adjust to constant changes as much, no eyestrain is the result.

6500k is not for video pictures, it is the color temperature for the whitest whites. Get your facts straight. Video pictures change from scene to scene, so they cannot just be 6500k

[Geoffcin]

My sister has the Philips with multi-color ambi-light. That thing is a trip!

1.5x eh? So your saying I should be ~8ft from my 60"? Seems a little close to me.

[E-Stat]

The proper shade for the front wall should be black. His wife should really stay out of this one, as she is trying to be decorative when in reality this should be more for performance and function.
One of my (single) audio buddies took a slightly different approach with his dedicated video room to meet the same objective. While the walls are green, he taped black plastic sheets across all the windows in the room so that no outside light enters. Not WAF friendly in the least. :)

rw

[E-Stat]

they sell it
Who is "they"?

rw

[Smokey]

When you sit too far away in a dark room(the proper way to watch movies), and you have a bright source constantly changing light levels in darkness, that is the problem as it makes the pupils rapidly have to adjust to the changing light levels. When you sit closer, there is more light hitting the pupils, which allows them to stay more open, and not have to rapidly adjust to constant changes as much, no eyestrain is the result.

This is just some thoughts (non projection TV), but I imagine sitting closer to TV (to fill in the field of view) would intensify the light that is hitting pupils in a dark room, thus pupils still have to adjust from darker scene to lighter scene. I still don't see how moving closer to TV would reduce constant change of pupils which is source of eye strain.

I agree with Pix that if planning to use an ambient light behind TV, the wall behind TV should be painted 6500k color temperature to accommodate the color temperature of calibrated TV.

[PeruvianSkies]

Who is "they"?

rw

Oh you know...the "people" upstairs.....

[Mingus]

Thanks for all the advice. The only problem my neighbor has now is a large rear window with a southern exposure which transmit lots of glare. They have to get some window treatment for it. Any advice on this.

[Sir Terrence the Terrible]

This is just some thoughts (non projection TV), but I imagine sitting closer to TV (to fill in the field of view) would intensify the light that is hitting pupils in a dark room, thus pupils still have to adjust from darker scene to lighter scene. I still don't see how moving closer to TV would reduce constant change of pupils which is source of eye strain.

If the set is filling your field of view, you are not that much in the darkness of the room. Yes, you are right, sitting closer does increase the intensity of the light, but it also reduces the influence of the dark room as well. The pupils get narrow in the light, and wider in the dark. If it sees mostly light(with the reduced influence of the dark) it will stay mostly closed with only small adjustments when the picture gets darker. If you are sitting far away, the dark will keep the pupil wide open, and when the light on the screen get brighter or darker, it will have to respond quickly to those changes which causes eye strain.


I agree with Pix that if planning to use an ambient light behind TV, the wall behind TV should be painted 6500k color temperature to accommodate the color temperature of calibrated TV.

If you paint the wall that white, then the contrast of that set will be greatly reduced. If you calibrate to that level of white, your blacks will surely be grey.

[Sir Terrence the Terrible]

My sister has the Philips with multi-color ambi-light. That thing is a trip!

1.5x eh? So your saying I should be ~8ft from my 60"? Seems a little close to me.

If your set is a 1080p, any further away and you will not see all that resolution. I sit exactly 7ft from my 55", and I have had no problems with that distance. No bias light needed, and at this distance I meet both SMPTE and THX specs for ideal viewing angle.

[Sir Terrence the Terrible]

Thanks for all the advice. The only problem my neighbor has now is a large rear window with a southern exposure which transmit lots of glare. They have to get some window treatment for it. Any advice on this.

Two words...blackout Curtains.

[Smokey]

If you are sitting far away, the dark will keep the pupil wide open, and when the light on the screen get brighter or darker, it will have to respond quickly to those changes which causes eye strain.

Couldn't the same argument also be made (in reverse) when sitting closer to TV where pupil will keep narrow due to light? It still have to respond to dark scenes by widening.

If there was constant light output from TV, then I would definitely agree with your argument. But since light output from TV is constantly changing (like from night to day time scene), I imagine pupil response is also changing whether sitting closer or further.



If you paint the wall that white, then the contrast of that set will be greatly reduced. If you calibrate to that level of white, your blacks will surely be grey.

You are corret there, and as you know it is suggested to keep ambient light intensity shinning on back wall much lower than TVs. Good test is that If you could read words on a paper with ambinet light on, then the light output is too high and should be lowered.

I have the ambinet light behind my TV so low that I can't barley read letters on my keyboard since computer is the same room.

[Sir Terrence the Terrible]

Couldn't the same argument also be made (in reverse) when sitting closer to TV where pupil will keep narrow due to light? It still have to respond to dark scenes by widening.

But not quite as much than if a dark room dominated my vision, and I was staring at a bright light within that darkness.


If there was constant light output from TV, then I would definitely agree with your argument. But since light output from TV is constantly changing (like from night to day time scene), I imagine pupil response is also changing whether sitting closer or further.

There is constant light output from the television, it is not consistently the same brightness but there is more light hitting the pupil with more intensity. The changes it has to make are more gradual than if the darkness was dominating(keeping the pupil more open most of the time). This reduces the eyestrain without the need of a bias light.





You are corret there, and as you know it is suggested to keep ambient light intensity shinning on back wall much lower than TVs. Good test is that If you could read words on a paper with ambinet light on, then the light output is too high and should be lowered.

I agree with this.


I have the ambinet light behind my TV so low that I can't barley read letters on my keyboard since computer is the same room.

How big is the screen, and how far do you sit from it.

[Smokey]

How big is the screen, and how far do you sit from it.

The screen size is 32 inch (SD :D) and I sit about 8 feet from TV. I think the proper distance to see full resolution would be around 11 feet, but am restricted to 8.

If I get a 37 inch HD which hopefully will be soon, I think the proper sitting distance would be around 5 feet. I tried sitting 5 feet from 32 inch and it seem too close to me as my eyes get bothered by TV being so close. So may have to keep distance of 8 feet for 37 incher also.

[pixelthis]

This is just some thoughts (non projection TV), but I imagine sitting closer to TV (to fill in the field of view) would intensify the light that is hitting pupils in a dark room, thus pupils still have to adjust from darker scene to lighter scene. I still don't see how moving closer to TV would reduce constant change of pupils which is source of eye strain.

I agree with Pix that if planning to use an ambient light behind TV, the wall behind TV should be painted 6500k color temperature to accommodate the color temperature of calibrated TV.

Thanks, Smoke.
This has been a bone of contention with the bone-head for some time, but I stand by
what I say, you need a decent backlight, doesn't have to be bright, can be dim, but it
will enhance viewing a great deal, also time you can watch video without tiring.
Mine is on a dimmer , not a wall dimmer, they can produce interference, a light remote
with dimmer, and I usually set it at a level fitting the source. But there will always be the
hermit in a dark room crowd.:1:

[Sir Terrence the Terrible]

The screen size is 32 inch (SD :D) and I sit about 8 feet from TV. I think the proper distance to see full resolution would be around 11 feet, but am restricted to 8.

If I get a 37 inch HD which hopefully will be soon, I think the proper sitting distance would be around 5 feet. I tried sitting 5 feet from 32 inch and it seem too close to me as my eyes get bothered by TV being so close. So may have to keep distance of 8 feet for 37 incher also.

You made my point, thanks! Bias lights are really for smaller screens in dark rooms where people sit too far from the set to fill the field of view.

5ft on a 32" SD set is quite close. You are going to see the scan lines from the distance. 5ft from a 37" HD set will not have that effect at all.

I sit 7ft from a 55", and it is like being at the theater because the set is properly calibrated(it is not blinding me with light), and with the lights off it look like the images are just floating in free space. I can see every bit of the 1080p resolution, and I have never needed a backlight and have never had any eye strain whatsoever even when viewing for long periods of time.

55" from 7ft away gives me a 36 degree wide viewing angle which meets THX recommended viewing angle for widescreen set ups. The maximum distance I can sit and still see all of the resolution of 1080p is 8.3ft.

[pixelthis]

Oh you know...the "people" upstairs.....

In your case, your parents, maybe? :1:

[pixelthis]

The screen size is 32 inch (SD :D) and I sit about 8 feet from TV. I think the proper distance to see full resolution would be around 11 feet, but am restricted to 8.

If I get a 37 inch HD which hopefully will be soon, I think the proper sitting distance would be around 5 feet. I tried sitting 5 feet from 32 inch and it seem too close to me as my eyes get bothered by TV being so close. So may have to keep distance of 8 feet for 37 incher also.

Saw one in the sales papers today for 499. EXCELLENT for a smaller HT, got rid of mine
because the screen just wasn't big enough, a 40" isn't that much more, you know, and at that size you start to get a feeling of movement , a more dimensional image, deeper.
Just make sure its a 1080p, trust me on this one.:1:

[Sir Terrence the Terrible]

Thanks, Smoke.
This has been a bone of contention with the bone-head for some time, but I stand by
what I say, you need a decent backlight, doesn't have to be bright, can be dim, but it
will enhance viewing a great deal, also time you can watch video without tiring.
Mine is on a dimmer , not a wall dimmer, they can produce interference, a light remote
with dimmer, and I usually set it at a level fitting the source. But there will always be the
hermit in a dark room crowd.:1:

Look, you recommended the entire room be 6500k, which is ridiculous. An all white room will kill the contrast of the set, and cause blacks to look a solid grey after you calibrate your set in a room this shade. How stupid is that!

Bias lights are more helpful when the set is small, and you sit far away from it. Otherwise, it is pretty much unnecessary when you sit the proper distance away from the set.

Do you see any bias lights in a movie theater? No! The small lights you see down the isleways are not nearly enough light to counter what is happening on that big screen.

[audio amateur]

Sir T, I also have a (widescreen) 32" SD screen. What's the rule for viewing distance here?

[Geoffcin]

If your set is a 1080p, any further away and you will not see all that resolution. I sit exactly 7ft from my 55", and I have had no problems with that distance. No bias light needed, and at this distance I meet both SMPTE and THX specs for ideal viewing angle.

Your inherently wrong there. Your basing your opinion on an idea that all people have similar visual acuity. This is simply not so. Although it's been getting worse, my eyesight is a measured 20/15 with my left eye closer to 20/10. Many people have similar ability natually, and also with optically corrected vision. 20/10 is TWICE the resolution of 20/20, which is what I assume your measurment is for. So taking your measurments and adding in my personal data I could be sitting somewhere between 50% to 100% FURTHER away and still manage to pick up all the available detail.

Of course none of this takes into account the temporal aspect of visual observation. Movement, especially fast movement, lowers the brains ability to process detail in real time. So with fast moving action I should be sitting even CLOSER. Studies have shown that in high detail situation that are moving fully 90% of the detail is discarded by the brain. If we take this into account and use your numbers then I should be sitting 90% closer to the screen! That would put me about 1ft away from my 60" screen. It would be quite absurd to sit that close, but at least I would get all the detail. On the other hand, I think I'll stay about~12ft away for now.

[Sir Terrence the Terrible]

Your inherently wrong there. Your basing your opinion on an idea that all people have similar visual acuity. This is simply not so. Although it's been getting worse, my eyesight is a measured 20/15 with my left eye closer to 20/10. Many people have similar ability natually, and also with optically corrected vision. 20/10 is TWICE the resolution of 20/20, which is what I assume your measurment is for. So taking your measurments and adding in my personal data I could be sitting somewhere between 50% to 100% FURTHER away and still manage to pick up all the available detail.

The standards for viewing are not built around individual eye issues, they are based around 20/20 viewing. So i am not inherently wrong here. Your personal issues are your personal issues, this has nothing to do with establishing a standard viewing distance.


Of course none of this takes into account the temporal aspect of visual observation. Movement, especially fast movement, lowers the brains ability to process detail in real time. So with fast moving action I should be sitting even CLOSER. Studies have shown that in high detail situation that are moving fully 90% of the detail is discarded by the brain. If we take this into account and use your numbers then I should be sitting 90% closer to the screen! That would put me about 1ft away from my 60" screen. It would be quite absurd to sit that close, but at least I would get all the detail. On the other hand, I think I'll stay about~12ft away for now.

Since you have no definition of what is considered fast motion, then I cannot see how your theory would oppose and nullify the standards that are set. This is an air sandwich as far as I am concerned. What is fast motion, define the speed. How does that correlate to moving action on a television screen. Does this indentifiy the outdoors, or watching television. Is this based on movement of both objects, or a single object with the viewer stationary. In other words, How does this "information" fit into television viewing, of which we are stationary, and the object travel to fixed distance defined by the size of the screen?

Without some sort of context, you last paragraph is meaningless. SMPTE and THX came to their conclusions based on testing with TELEVISIONS specifically, not just regular everyday viewing we do outdoors.

[Geoffcin]

The standards for viewing are not built around individual eye issues, they are based around 20/20 viewing. So i am not inherently wrong here. Your personal issues are your personal issues, this has nothing to do with establishing a standard viewing distance.



Since you have no definition of what is considered fast motion, then I cannot see how your theory would oppose and nullify the standards that are set. This is an air sandwich as far as I am concerned. What is fast motion, define the speed. How does that correlate to moving action on a television screen. Does this indentifiy the outdoors, or watching television.

Without some sort of context, you last paragraph is meaningless. SMPTE and THX came to their conclusions based on testing with TELEVISIONS specifically, not just regular everyday viewing we do outdoors.

Again, your just posting what you've been told. These guidelines are meaningless unless you can understand what they convey. And what they convey is a simplistic understanding of visual acuity at best. To say that this "seating distance rule" should be based on the simple 20/20 arc-minute acuity rule that sitting an exact distance from the set and viewing a static image would get you, as if you were watching a screen like you reading a Snellen test chart is absurd. Everything is in motion on screen.

I am a little shocked though that someone working for the industry has never heard of static visual acuity vs.dynamic visual acuity. In my field, Aerospace engineering, we've heard of these terms, and they are in regular use when it comes to engineering displays for aircraft.

[Sir Terrence the Terrible]

Again, your just posting what you've been told. These guidelines are meaningless unless you can understand what they convey. And what they convey is a simplistic understanding of visual acuity at best. To say that this "seating distance rule" should be based on the simple 20/20 arc-minute acuity rule that sitting an exact distance from the set and viewing a static image would get you, as if you were watching a screen like you reading a Snellen test chart is absurd. Everything is in motion on screen.


I am a little shocked though that someone working for the industry has never heard of static visual acuity vs.dynamic visual acuity. In my field, Aerospace engineering, we've heard of these terms, and they are in regular use when it comes to engineering displays for aircraft.

The Aerospace field is different from the movie industry, wouldn't you agree? So it would stand to reason their recommendations would be based on different principles.

An Aircraft display is quite different than a consumer display right? So it would stand to reason there would be different reasons why different standards would be applied to different displays.

None of what you are saying here is applicable to why the standards were developed. So you have a complete understanding of why SMPTE and THX have recommended the viewing distances they have might be better served by just reading their justifications

THX

THX recommends that the “best seat-to-screen distance” is one where the view angle approximates 40 degrees (the actual angle is 40.04 degrees). Their recommendation was originally presented at the 2006 CES show, and was stated as being the theoretical maximum horizontal view angle, based on average human vision. In the opinion of THX the location where the display is viewed at a 40 degree view angle provides the most “immersive cinematic experience”, all other things considered. For consumer application of their recommendations, THX recommends dividing the diagonal screen measurement by .84 to calculate the optimum viewing distance, for an 1080p resolution.

SMPTE

Viewing an HDTV from a position where the display occupies a 30 degree field of view is widely quoted as the SMPTE (or SMPTE 30) recommendation. This recommendation is very popular with the home theater enthusiast community, appears in books on home theater design, and is also supported by a white paper produced by Fujitsu

So while you are looking at other issues, they base their recommendation on the most "immersive experience", not static versus kinetic visual acuity which you are addressing.

It is not wise to try and apply principles directed at the Aerospace industry towards the film industry. Their reasoning for their principles are quite different.

[Geoffcin]

So, is it 30 degrees or 40.04? Perhaps I'm missing something but the most "immersive cinematic experience” seems a little vague to me. How was that defined, or did a bunch of THX engineers just sit in a screening room and say; That's what looks coolest to us"

It's pretty telling that their recommendation turns out to exactly match the 1 arc-minute standard used for calcualting 20/20 vision on a static chart.

For me I like the 30 degree rule better, but it would matter on the subject material. If it's a romantic comedy 3 degrees would be too much for me.

Oh, and off topic; PS is getting a PM from me about his sig. It will be changed.

[pixelthis]

Sir T, I also have a (widescreen) 32" SD screen. What's the rule for viewing distance here?

THROW out your obsolete set and get a decent HDTV, at least 37".
And use a backlight. Sir talky calls it a bias light, but no matter what your screen size you need one(Talky wrong again).
No, you dont need one in a theater, but even with a 100 in screen , your screen is small compared to a theater, and you need one or several backlights to even out the light in your room , and reduce eyestrain.
THINK YOU CAN SIT IN A DARK ROOM and watch video? fine, do so.
BUT JUST REMEMBER, you can't get new eyes at Best Buy.
ASK anybody with eye problems how much fun they are. FUNNY HOW HT fans obsess
over their gear, except for the two irreplaceable and most valuable pieces of gear,
ears and eyes.
USE A BACKLIGHT. :1:

[audio amateur]

THROW out your obsolete set and get a decent HDTV, at least 37".
And use a backlight. Sir talky calls it a bias light, but no matter what your screen size you need one(Talky wrong again).
No, you dont need one in a theater, but even with a 100 in screen , your screen is small compared to a theater, and you need one or several backlights to even out the light in your room , and reduce eyestrain.
THINK YOU CAN SIT IN A DARK ROOM and watch video? fine, do so.
BUT JUST REMEMBER, you can't get new eyes at Best Buy.
ASK anybody with eye problems how much fun they are. FUNNY HOW HT fans obsess
over their gear, except for the two irreplaceable and most valuable pieces of gear,
ears and eyes.
USE A BACKLIGHT. :1:
I will purchase a projector when the funds arrive:) In the meantime, Im doing with this screen that I got dirt cheap about a month ago.

[Mingus]

My viewing distance in the LR is 15 ft for a 720p 50" screen, BR is 12 ft for 1080p 40",screen and basement 12 ft for 1080p 46" screen. I do have back lighting for all the sets. This might help a little. For me it seems OK, however maybe I am just use to it.

[filecat13]

Perhaps Mingus can clarify this, but the OP use of the word "screen" seems clearly to be referencing a projection screen, not a television or monitor. If that truly is the case, then all the carrying on about back lighting or bias lighting the screen is nonsense. If the case is that it's a TV or monitor, then things are different.

Those who use TVs or monitors in their systems are well advised to do what many recommend and give their eyes some help. OTOH, if you're using a projector and screen, It's complete and utter nonsense to think about backlighting or bias lighting your projection wall.

In the home theater (similar to a commercial theater) where one is using a projector and AT screen, the notion of backlighting is beyond ludicrous.

[Sir Terrence the Terrible]

So, is it 30 degrees or 40.04? Perhaps I'm missing something but the most "immersive cinematic experience” seems a little vague to me. How was that defined, or did a bunch of THX engineers just sit in a screening room and say; That's what looks coolest to us"

For Hometheater it is 36 degrees, for the theater it is 40.04. 30 degrees for SMPTE is for smaller theaters with screens that are a more moderate size than what we currently see in theaters now. 30 degrees is their minimum, and 36 is their maximum for larger theaters we currently have. They actually conducted individual tests over a period of 5 years using a large sample of viewers, and they also based their tests on a white that Fujitsu submitted to SMPTE a while ago.


It's pretty telling that their recommendation turns out to exactly match the 1 arc-minute standard used for calcualting 20/20 vision on a static chart.

For me I like the 30 degree rule better, but it would matter on the subject material. If it's a romantic comedy 3 degrees would be too much for me.

LOL, I get that last statement! I admit, if you are not used to looking at a screen with a 36 degree viewing angle, it would probably make me uncomfortable as well. But after 25 years of working on sound for film, I have gotten so used to it, that nothing else works for me.


Oh, and off topic; PS is getting a PM from me about his sig. It will be changed.

Thank you much for the resolution.

[Mingus]

Perhaps Mingus can clarify this, but the OP use of the word "screen" seems clearly to be referencing a projection screen, not a television or monitor. If that truly is the case, then all the carrying on about back lighting or bias lighting the screen is nonsense. If the case is that it's a TV or monitor, then things are different.

Those who use TVs or monitors in their systems are well advised to do what many recommend and give their eyes some help. OTOH, if you're using a projector and screen, It's complete and utter nonsense to think about backlighting or bias lighting your projection wall.

In the home theater (similar to a commercial theater) where one is using a projector and AT screen, the notion of backlighting is beyond ludicrous.

Just spoke to my neightbor and not really sure what system he is using. For me, I am using television monitors.

[bfalls]

Kudos Sir T. I agree with all you've said. It's the same I learned in ISF certification. You've provided excellent information with explanation most should understand. You'll always going to run into those who do things because "it's the way I like it", or "the way we've always done it before" and those who just want to disagree because you're Sir T. You won't change their minds, but don't stop trying. The rest of us understand and appreciate the education. Maybe instead of worrying about visual acuity, the focus should be on density.

[pixelthis]

Perhaps Mingus can clarify this, but the OP use of the word "screen" seems clearly to be referencing a projection screen, not a television or monitor. If that truly is the case, then all the carrying on about back lighting or bias lighting the screen is nonsense. If the case is that it's a TV or monitor, then things are different.

Those who use TVs or monitors in their systems are well advised to do what many recommend and give their eyes some help. OTOH, if you're using a projector and screen, It's complete and utter nonsense to think about backlighting or bias lighting your projection wall.

In the home theater (similar to a commercial theater) where one is using a projector and AT screen, the notion of backlighting is beyond ludicrous.

Don't hold back, tell up what you really think.
Unless you have your own amphitheater, the max on most home "screens"( a term which
covers both direct view and projectors) is around a 100".
Sounds big, right? Well, compared to WHAT?
A commercial screen in a movie theater, which is usually THIRTY FEET?
Or larger, most times.
A venue screen, which can run fifty to two hundred feet?
Like talkys girlfriend, its all relative, certain screens might seem big, but a ten footer is
a shrimp compared to the movies, which is why I still go, on occasion.
You don't have to light it up like gods waiting room, but some lighting in any HT room can't hurt.:1:

[pixelthis]

Look, you recommended the entire room be 6500k, which is ridiculous. An all white room will kill the contrast of the set, and cause blacks to look a solid grey after you calibrate your set in a room this shade. How stupid is that!

Bias lights are more helpful when the set is small, and you sit far away from it. Otherwise, it is pretty much unnecessary when you sit the proper distance away from the set.

Do you see any bias lights in a movie theater? No! The small lights you see down the isleways are not nearly enough light to counter what is happening on that big screen.

WHICH IS THE POINT, the movies are a BIIIIG screen.:1:

[Sir Terrence the Terrible]

WHICH IS THE POINT, the movies are a BIIIIG screen.:1:

When I sit 7ft from a 55" and get a 36 degree viewing angle, the television seems really big as well. That is why a bias light is unnecessary, and that is exactly my point!

[filecat13]

Don't hold back, tell up what you really think.
Unless you have your own amphitheater, the max on most home "screens"( a term which
covers both direct view and projectors) is around a 100".
Sounds big, right? Well, compared to WHAT?
A commercial screen in a movie theater, which is usually THIRTY FEET?
Or larger, most times.
A venue screen, which can run fifty to two hundred feet?
Like talkys girlfriend, its all relative, certain screens might seem big, but a ten footer is
a shrimp compared to the movies, which is why I still go, on occasion.
You don't have to light it up like gods waiting room, but some lighting in any HT room can't hurt.:1:

Really, I am holding back, but thanks for your permission.

Since the term "screen" covers many definitions, I asked for clarification. The OP gave it. Your need to bring up an answered inquiry is irrelevant.

In my case it's 110", a trifle larger than 100". However, math and logic can be our friend, so follow me. A viewing distance of 12' on a 110" diagonal 16:9 screen gives a viewing angle of 36.8 degrees. The SMPTE standard EG-18-1994 recommends a minimum viewing angle of 30 degrees and THX recommends 36 degrees. These recommendations are based on 20/20 vision, and these fields of view (or closer) will result in a more immersive experience, and also lessen eye strain caused by watching a smaller image in a dark room. These principles apply at home and at the cinema.

Just for grins, if a cinema has a 60' wide screen in 16:9 ratio, then you have to sit 90 feet from the screen to replicate the viewing angle in my little HT. For a 40' screen the distance would be 60 feet. Everybody knows the formula by now.

Let's put someone's 55" TV in the formula. A viewing distance of 7' gives a 31.9 degree viewing angle: SMPTE says "okay" while THX says "not quite." At 6', you've got 36.8 degrees, so THX is happy, too. That is identical to what I get in my HT with my 110" screen. As Mr. T has said many times, at that distance, nothing more is needed.

But wait a minute! My small 46" Sharp LCDTV in the bedroom gets watched from nearly 14 feet away on the love seat or 17 feet away on the bed. There is no way I'd watch that thing from 6' away for any period of time. I'd have to sit on the floor or put the seat in the middle of the room. At the comfortable distances I do watch from, the viewing angle is something around 13 degrees. So my field of vision is much wider than what I'm watching, and, yes, I do keep an ambient light on so my eyes don't strain in that case.

Nonetheless, when my field of vision is engulfed by the screen down in the HT, no lights are allowed. My GF even complains about the blue LEDs on the amps polluting the room with light. So, even without my own amphitheater, I can replicate the viewing conditions of a cinema.

Just for completion for the OP, the screen wall is covered top to bottom with acoustical panels ranging from 1" to 4" thick depending on location. They are covered in black cloth, so the entire wall absorbs sound and light, truly a "dead end." The side and rear walls are painted a dark, flat chocolate color, as are the front two quarters of the ceiling. (The ceiling is divided into four quadrants to break up sound.) Black velour curtains cover the front half of each side wall as well, helping to break up early reflections, and the rest of the walls have acoustical panels, sound diffusers, and surround speakers at appropriate locations. Against the chocolate walls the panels are covered in chocolate-colored cloth, and the diffusers (Steven Klein Sound Room Saturns) are painted the same color as the walls.

I left the two rear ceiling quadrants a sort of dusky white to avoid the total man cave stigma for guests, and the equipment racks are inset into the left side wall near the rear of the room. Most of the equipment allows the status lights to be turned off, but the amps do not, hence the complaints about the blue LEDs polluting the room. I had a custom panel designed to put in front that blocks the light but not the air flow.

Each user can determine how he/she wants to handle light in the HT. But there are reasons we endeavor to have light controlled rooms and dark walls to cut light reflections. In my case, those reasons do not include making a light controlled room so I can leave on a light while watching a movie. :mad2:

[Smokey]

However, math and logic can be our friend, so follow me. A viewing distance of 12' on a 110" diagonal 16:9 screen gives a viewing angle of 36.8 degrees. The SMPTE standard EG-18-1994 recommends a minimum viewing angle of 30 degrees and THX recommends 36 degrees.These recommendations are based on 20/20 vision, and these fields of view (or closer) will result in a more immersive experience, and also lessen eye strain caused by watching a smaller image in a dark room.

Given that SMPTE and THX sitting distance recommendations are primary based on eye capabilty to see full TV resolution, I don't think eye strain or fatigue come into play for those recommendations.

For example, if you change the TV resolution from 1080 to 720p or 480, your sitting distance will also have to change (sit further) so your eyes can see TV's full resolution. So as you can see, eye fatigue is not a factor in those sittings recommendations.



That is identical to what I get in my HT with my 110" screen. As Mr. T has said many times, at that distance, nothing more is needed.

Ambient light recommendation are primary for non projection systems. So your HT do not qualify :)

[Sir Terrence the Terrible]

Really, I am holding back, but thanks for your permission.

Since the term "screen" covers many definitions, I asked for clarification. The OP gave it. Your need to bring up an answered inquiry is irrelevant.

In my case it's 110", a trifle larger than 100". However, math and logic can be our friend, so follow me. A viewing distance of 12' on a 110" diagonal 16:9 screen gives a viewing angle of 36.8 degrees. The SMPTE standard EG-18-1994 recommends a minimum viewing angle of 30 degrees and THX recommends 36 degrees. These recommendations are based on 20/20 vision, and these fields of view (or closer) will result in a more immersive experience, and also lessen eye strain caused by watching a smaller image in a dark room. These principles apply at home and at the cinema.

Just for grins, if a cinema has a 60' wide screen in 16:9 ratio, then you have to sit 90 feet from the screen to replicate the viewing angle in my little HT. For a 40' screen the distance would be 60 feet. Everybody knows the formula by now.

Let's put someone's 55" TV in the formula. A viewing distance of 7' gives a 31.9 degree viewing angle: SMPTE says "okay" while THX says "not quite." At 6', you've got 36.8 degrees, so THX is happy, too. That is identical to what I get in my HT with my 110" screen. As Mr. T has said many times, at that distance, nothing more is needed.

But wait a minute! My small 46" Sharp LCDTV in the bedroom gets watched from nearly 14 feet away on the love seat or 17 feet away on the bed. There is no way I'd watch that thing from 6' away for any period of time. I'd have to sit on the floor or put the seat in the middle of the room. At the comfortable distances I do watch from, the viewing angle is something around 13 degrees. So my field of vision is much wider than what I'm watching, and, yes, I do keep an ambient light on so my eyes don't strain in that case.

Nonetheless, when my field of vision is engulfed by the screen down in the HT, no lights are allowed. My GF even complains about the blue LEDs on the amps polluting the room with light. So, even without my own amphitheater, I can replicate the viewing conditions of a cinema.

Just for completion for the OP, the screen wall is covered top to bottom with acoustical panels ranging from 1" to 4" thick depending on location. They are covered in black cloth, so the entire wall absorbs sound and light, truly a "dead end." The side and rear walls are painted a dark, flat chocolate color, as are the front two quarters of the ceiling. (The ceiling is divided into four quadrants to break up sound.) Black velour curtains cover the front half of each side wall as well, helping to break up early reflections, and the rest of the walls have acoustical panels, sound diffusers, and surround speakers at appropriate locations. Against the chocolate walls the panels are covered in chocolate-colored cloth, and the diffusers (Steven Klein Sound Room Saturns) are painted the same color as the walls.

I left the two rear ceiling quadrants a sort of dusky white to avoid the total man cave stigma for guests, and the equipment racks are inset into the left side wall near the rear of the room. Most of the equipment allows the status lights to be turned off, but the amps do not, hence the complaints about the blue LEDs polluting the room. I had a custom panel designed to put in front that blocks the light but not the air flow.

Each user can determine how he/she wants to handle light in the HT. But there are reasons we endeavor to have light controlled rooms and dark walls to cut light reflections. In my case, those reasons do not include making a light controlled room so I can leave on a light while watching a movie. :mad2:

This man get's it!!!

I remeasured my distance to my 55" and I was mistaken. It was 6ft, not 7ft. When I created this setup, I knew I had followed THX distance guidelines when setting up the distance to the viewing seat.

[Sir Terrence the Terrible]

Given that SMPTE and THX sitting distance recommendations are primary based on eye capabilty to see full TV resolution, I don't think eye strain or fatigue come into play for those recommendations.

For example, if you change the TV resolution from 1080 to 720p or 480, your sitting distance will also have to change (sit further) so your eyes can see TV's full resolution. So as you can see, eye fatigue is not a factor in those sittings recommendations.

Agreed


Ambient light recommendation are primary for non projection systems. So your HT do not qualify :)

Three of my HT's are non projection systems, and I don't use bias lights on any of them. Viewing distance is what determines the need for a bias light. Since most folks don't sit close enough to the televisions, it is needed. For those folks like myself who do, they are totally unnecessary. SMPTE and THX guidelines can be used on any HDTV display, not just on projection systems.

[pixelthis]

This man get's it!!!

I remeasured my distance to my 55" and I was mistaken. It was 6ft, not 7ft. When I created this setup, I knew I had followed THX distance guidelines when setting up the distance to the viewing seat.

You "get" it too.
Eyestrain, macular degeneration, shortened viewing times, etc.
BUT IF YOU so enjoy sitting in the dark like a hermit watching whatever you do watch...:1:

[Smokey]

Viewing distance is what determines the need for a bias light. Since most folks don't sit close enough to the televisions, it is needed.

I would say that is a fair statement. By looking at SMPTE and THX guidelines for sitting distance (1080p)....

30 inch TV= 4 feet
34 inch TV= 4.5 feet
40 inch TV= 5.3 feet
50 inch TV= 6.5 feet
60 inch TV= 8 feet

...it become obvious why most people do not sit close enough. The viewing distance seem too short.

[Sir Terrence the Terrible]

I would say that is a fair statement. By looking at SMPTE and THX guidelines for sitting distance (1080p)....

30 inch TV= 4 feet
34 inch TV= 4.5 feet
40 inch TV= 5.3 feet
50 inch TV= 6.5 feet
60 inch TV= 8 feet

...it become obvious why most people do not sit close enough. The viewing distance seem too short.

Considering most folks are continuing the viewing distance habits they developed from watching SD television at 480i resolution, no wonder they think the distance it too short. When viewing HDTV images, you have to sit closer so you can see the detail in those pixels, there is more than enough resolution for a closer seat. Scan lines are no longer a worry, because there are none. Folks just have not changed their habits to reflect the fact they are seeing far more resolution than they are used to. What adds to this, is that most folks do not get their televisions properly calibrated, so sitting closer to something that is effectively burning their eyes out is probably not that comfortable.

I would imagine that when 4K resolution hits the streets, they will still be sitting where they were sitting when 480i ruled the roost!

[pixelthis]

I would say that is a fair statement. By looking at SMPTE and THX guidelines for sitting distance (1080p)....

30 inch TV= 4 feet
34 inch TV= 4.5 feet
40 inch TV= 5.3 feet
50 inch TV= 6.5 feet
60 inch TV= 8 feet

...it become obvious why most people do not sit close enough. The viewing distance seem too short.

I dunno, thats about where I sit for my 42"...:1:

[Smokey]

I would imagine that when 4K resolution hits the streets, they will still be sitting where they were sitting when 480i ruled the roost!

I hate to see THX/SMPTE sitting recommendations for 4k resolution TV which the stitting will be even closer than 1080 TVs. But at some point, the eye "burn out" will definitely become a factor.


I dunno, thats about where I sit for my 42"...

Then you don't need a bias light :D

Not withstanding seeing scan lines (SD) I tried different sittng distances from 32 inch TV, and eye comfort zone seem to be around 8 feet.

[pixelthis]

I hate to see THX/SMPTE sitting recommendations for 4k resolution TV which the stitting will be even closer than 1080 TVs. But at some point, the eye "burn out" will definitely become a factor.


Don't worry about it, we will get 4k TV about the time we get warp drive and decent microwave
pizza.:1:

[Sir Terrence the Terrible]

I hate to see THX/SMPTE sitting recommendations for 4k resolution TV which the stitting will be even closer than 1080 TVs. But at some point, the eye "burn out" will definitely become a factor.
.

Actually you won't be sitting any closer, the screen is going to have to get much bigger than the ones we see now. 4K on a 100" screen= waste of resolution. You are going to need something closer to 150" to get any benefit from 4K

[Johnny B. Galt]

I would say that is a fair statement. By looking at SMPTE and THX guidelines for sitting distance (1080p)....

30 inch TV= 4 feet
34 inch TV= 4.5 feet
40 inch TV= 5.3 feet
50 inch TV= 6.5 feet
60 inch TV= 8 feet

...it become obvious why most people do not sit close enough. The viewing distance seem too short.

I'm soon to be shopping for a new TV. While these distances are the standards for 1080p material and would be the ideal for viewing when I'm watching a Blu-ray movie, that's only about a quarter of my viewing. Do you have any guidelines for suggested viewing (or screen size based on where the couch is) for general viewing of lower resolution content? My television viewing is a mix of non-HD cable programs and OTA HD major network sports broadcasts.

[Smokey]

Hi Johnny

You didn't mention the screen TV size, but.....

For 720P HD sources, recommended sitting distance is..

20 inch TV= 4 feet
26 inch TV= 5 feet
30 inch TV= 6 feet
34 inch TV= 6.7 feet
40 inch TV= 8 feet
50 inch TV= 10 feet
60 inch TV= 12 feet

For DVD/non-hd cable (480p) source, recommended sitting distance is..

20 inch TV= 7 feet
26 inch TV= 9 feet
30 inch TV= 10.5 feet
34 inch TV= 12 feet
40 inch TV= 14 feet
50 inch TV= 17.5 feet
60 inch TV= 21 feet.

Hope that help.

[Johnny B. Galt]

Thanks, Smokey! It is good to have all recommended distances in one spot. It looks like I'm going to have to shop for a couch with wheels on it based on my viewing! I've been looking at sets between 46 and 55 inches and my tentative seating position is about ten feet. I'd love to have a dedicated "theater" which was optimized for movies but realize I'm going to have to make compromises as most viewing will not be blu-ray. Looks like I'll also be reading the new a/v receiver reviews very carefully for upscaling performance.

I've enjoyed this thread although my wall color was decided back when I picked out the stone. However, this does make a case for going a little darker for the walls than I'd originally thought...

[Mingus]

Great information on this thread. I just found out my neightbor will be getting a 55 inch 1080p television with the main seating about 10 to 11 feet away. He will have backlighting.

[Geoffcin]

For DVD/non-hd cable (480p) source, recommended sitting distance is..

20 inch TV= 7 feet
26 inch TV= 9 feet
30 inch TV= 10.5 feet
34 inch TV= 12 feet
40 inch TV= 14 feet
50 inch TV= 17.5 feet
60 inch TV= 21 feet.

Hope that help.

Wow, don't pull out the old lo-fi VHS tapes or you'll be sitting somewhere in the neighbors house!

[GMichael]

I like this chart.

[pixelthis]

Great information on this thread. I just found out my neightbor will be getting a 55 inch 1080p television with the main seating about 10 to 11 feet away. He will have backlighting.

Your neighbor is very smart.
What a lot don't get is that you err on the side of caution with something you can't replace,
like a classic amp, or a set of eyes, is all I AM SAYING.:1:

[Sir Terrence the Terrible]

Your neighbor is very smart.
What a lot don't get is that you err on the side of caution with something you can't replace,
like a classic amp, or a set of eyes, is all I AM SAYING.:1:

If you understood how the eye works, then you would realize the profound ignorance of this statement.

[bobsticks]

I miss Slumpy and his purple home theater room...

[Sir Terrence the Terrible]

I miss Slumpy and his purple home theater room...

Is Slumpy cousins with Pookie? Inquiring minds want to know.

[pixelthis]

If you understood how the eye works, then you would realize the profound ignorance of this statement.

AND if you understood that they don't come in a blister pack at Sears, maybe you wouldn't
be so ignorant.
Do you realize how much they teach about how to use your eyes at the law enforcement
academy?
TEMPORARILY losing your sight when it gets dark, or suddenly light, is an inconvenience
sometimes, sometimes it can kill you.
All I am saying.:1:

[Sir Terrence the Terrible]

AND if you understood that they don't come in a blister pack at Sears, maybe you wouldn't
be so ignorant.
Do you realize how much they teach about how to use your eyes at the law enforcement
academy?
TEMPORARILY losing your sight when it gets dark, or suddenly light, is an inconvenience
sometimes, sometimes it can kill you.
All I am saying.:1:

Law enforcement....Hometheater...what a stretch. A properly calibrated set can not blind you, not even in the dark. Get a grip man!

[Johnny B. Galt]

[QUOTE=Sir Terrence the Terrible]Law enforcement....Hometheater...what a stretch.QUOTE]
He might be on to something...:
Popcorn with M&Ms doesn't seem particularly well-suited for my dog's digestive system but is usually served whenever I watch a movie. An eye must be kept on the dog so that she doesn't sneak a bowl full of the deliciously buttery/salty/sweet treats that can produce an eye-watering funk when passed through a yellow lab. The reason you have to trade your contact lenses for those sweet BCGs (birth control glasses) when you enter boot camp? Tear gas.

[pixelthis]

[QUOTE=Sir Terrence the Terrible]Law enforcement....Hometheater...what a stretch.QUOTE]
He might be on to something...:
Popcorn with M&Ms doesn't seem particularly well-suited for my dog's digestive system but is usually served whenever I watch a movie. An eye must be kept on the dog so that she doesn't sneak a bowl full of the deliciously buttery/salty/sweet treats that can produce an eye-watering funk when passed through a yellow lab. The reason you have to trade your contact lenses for those sweet BCGs (birth control glasses) when you enter boot camp? Tear gas.

You do know that chocolate is poisonous to doggies, don't you?:1:

[pixelthis]

Law enforcement....Hometheater...what a stretch. A properly calibrated set can not blind you, not even in the dark. Get a grip man!

GET A CLUE.
I err on the side of safety, I KEEP MY EYES.
You side (as usual) with being an arrogant prick that thinks he knows everything, and maybe you will be okay.
MAYBE you will be shopping for a new pair of eyes on CHINESE net sites(retinas, sixty grand a pair).:1: