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  1. #26
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by pixelthis
    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.
    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.
    Last edited by Geoffcin; 08-12-2010 at 05:51 AM.
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  2. #27
    Forum Regular audio amateur's Avatar
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    Sir T, I also have a (widescreen) 32" SD screen. What's the rule for viewing distance here?

  3. #28
    Silence of the spam Site Moderator Geoffcin's Avatar
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    Quote Originally Posted by Sir Terrence the Terrible
    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.
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  4. #29
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by Geoffcin
    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.
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  5. #30
    Silence of the spam Site Moderator Geoffcin's Avatar
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    Quote Originally Posted by Sir Terrence the Terrible
    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.
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  6. #31
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by Geoffcin
    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.
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  7. #32
    Silence of the spam Site Moderator Geoffcin's Avatar
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    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.
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  8. #33
    Forum Regular pixelthis's Avatar
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    Quote Originally Posted by audio amateur
    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.
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  9. #34
    Forum Regular audio amateur's Avatar
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    Quote Originally Posted by pixelthis
    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.
    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.

  10. #35
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    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.

  11. #36
    Forum Regular filecat13's Avatar
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    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.
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  12. #37
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by 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"
    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.
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  13. #38
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    Quote Originally Posted by 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.
    Just spoke to my neightbor and not really sure what system he is using. For me, I am using television monitors.

  14. #39
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    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.

  15. #40
    Forum Regular pixelthis's Avatar
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    Quote Originally Posted by 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.
    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.
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  16. #41
    Forum Regular pixelthis's Avatar
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    Thumbs up

    Quote Originally Posted by Sir Terrence the Terrible
    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.
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  17. #42
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by pixelthis
    WHICH IS THE POINT, the movies are a BIIIIG screen.
    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!
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  18. #43
    Forum Regular filecat13's Avatar
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    Thumbs up It's a long one...

    Quote Originally Posted by pixelthis
    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.
    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.
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  19. #44
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    Quote Originally Posted by filecat13
    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

  20. #45
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by filecat13
    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.
    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

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  21. #46
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by Smokey
    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.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  22. #47
    Forum Regular pixelthis's Avatar
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    Thumbs down

    Quote Originally Posted by Sir Terrence the Terrible
    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...
    LG 42", integra 6.9, B&W 602s2, CC6 center, dm305rears, b&w
    sub asw2500
    Panny DVDA player
    sharp Aquos BLU player
    pronto remote, technics antique direct drive TT
    Samsung SACD/DVDA player
    emotiva upa-2 two channel amp

  23. #48
    Suspended Smokey's Avatar
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    Quote Originally Posted by Sir Terrence the Terrible
    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.

  24. #49
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by Smokey
    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!
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  25. #50
    Forum Regular pixelthis's Avatar
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    Cool

    Quote Originally Posted by Smokey
    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"...
    Attached Images Attached Images  
    LG 42", integra 6.9, B&W 602s2, CC6 center, dm305rears, b&w
    sub asw2500
    Panny DVDA player
    sharp Aquos BLU player
    pronto remote, technics antique direct drive TT
    Samsung SACD/DVDA player
    emotiva upa-2 two channel amp

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