3D Television Opinion Thread - Page 5 - AVS Forum
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post #121 of 129 Old 02-05-2010, 09:20 AM
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Originally Posted by DaViD Boulet View Post

We don't have ambient lighting in a movie theater. So why should we have ambient light in our home theater?

So with HD in our homes, it really depends on what you're trying to do.

Do you want a "home theater"? If so, watch movies wide-angle on a large screen in a darkened room and calibrate accordingly. I would assume that's what you mean when you suggest "some sample of viewers".

Do you want to watch your HD display in a semi-lighted environment so others can casually view while they perhaps read or carry on other activities while one or more viewers watch the primary feature? Then calibrate for ambient light. That certainly describes the real-world environment for most HDTVs out there. But hanging an HDTV on your living room wall is not "home theater" per-se. It's not a bad thing either, but it's not replicating the art of cinema and we need to keep the two enviornments very distinct when we talk about our goals for high-performance image reproduction as home-theater enthusiasts.

Typical commercial cinema image- 8 to 10 foot Lamberts of screen brightness.
Typical SMPTE screening room cinema- =/> 12 fL.
Typical calibrated professional monitor- 30 to 35 fL.
Typical uncalibrated consumer television- 40 to 80 fL.

"Some samples of viewers" refers to the fact that some individuals are less sensitive to the causes of eye strain or headaches than others. Remember, this is the "Flat Panel General...." section of the forum. We're talking about 3D TVs, not projection display systems here. I don't know of a TV that will look right, even in a light-less room, if the peak brightness is reduced to 12 fL.

Reference viewing conditions for a TV-type monitor are standardized in the HD program production community. Such conditions include bias lighting due to human factors. The human visual system has limitations that must be taken into account when designing electronic display systems and/or calibrating them.

Most consumers cannot properly accommodated a front projection system in their home. A large screen HDTV, with surround sound audio, can be a reasonable and fulfilling alternative method of communicating cinematic art. This methodology can be most effective when the viewing and listening environment are conducive. Understanding human factors is essential to getting the most out of any entertainment system. The user is as much a vital component in system design as the gear. Unfortunately, human factors are the least understood element in most systems. Not all practices in front projection cinema work in direct-view display systems. Film imaging and exhibition best practices are also not equivalent to video imaging. The specific context needs to be understood and tracked to avoid confusion.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants Affiliate

"Advancing the art and science of electronic imaging"
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post #122 of 129 Old 02-05-2010, 11:49 AM
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Quote:
Originally Posted by DaViD Boulet View Post

Brightness is a component, but what's being missed is that the real purpose of bias-lighting is to fill the viewer's field of vision with an average light output in balance with the light output of the (small) TV screen on their wall to avoid eyestrain.

However, if your image *is* the wall, then your field of vision is already filled with average light levels. That's what you see in the theater... a large image that basically fills your field of vision. That's what you should also be seeing in your home-theater if you're replicating a cinema viewing angle.

Once you have an image that's filling your field of vision, there's no need for ambient bias-lighting because there's no empty field of vision that needs to be filled to make viewing comfortable. Regarding brightness of your image: when filling the field of vision of a 30 degree viewing angle, the ideal brightness of the image becomes an issue of viewing comfort: some folks like a bright an punch picture, others will prefer a more cinematic image with less brightness... but in either case image calibration and your eyes' natural adjustment to the average light levels will allow a proper viewing experience.

It's the image brightness extremes that are at issue with viewing fatigue/eye strain/headaches. Image size is only one component. Peak image brightness is still a critical factor due to the "strobing" effect of relatively rapid scene changes from dark to light composition. That is the real purpose of bias lighting. The supplemental illumination within your field of view moderates the pupil and retina changes in a dark adapted state. This is important for viewing relatively high-brightness images in a dark viewing environment, even at 30 degree viewing angles or greater. This is not necessary in front projection systems, unless unusually high peak image brightness is maintained in a dark theater.
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post #123 of 129 Old 02-05-2010, 11:59 AM
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Requiring glasses to watch tv is very cognitively challenged (retarded). Plus, I guess it doesn't matter with me 'cause I have a depth perception problem with my eyes which doesn't allow me to see 3d. So count me out.

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post #124 of 129 Old 02-06-2010, 08:05 PM
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Quote:
Originally Posted by DaViD Boulet View Post

However, if your image *is* the wall, then your field of vision is already filled with average light levels. That's what you see in the theater... a large image that basically fills your field of vision.

Actually...the human eye has a very small field of resolving vision. It's not like a camera at all.

Wherever your vision is focused, you'll get a blurring sensation on either side. This is quite apparent during the simple act of reading: you will have a hard time resolving text located just a couple of words either side of the word you're currently focused on.

"Peripheral vision" is more of a "sensation" than actual visual acuity.
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post #125 of 129 Old 02-26-2010, 09:32 AM
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Music players that required ear buds didn't make a lot of sense to me, but they took off. Shutter glasses - much less imposing than something stuck in my ear.
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post #126 of 129 Old 02-26-2010, 11:32 AM
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Quote:
Originally Posted by PrimeTime View Post

Actually...the human eye has a very small field of resolving vision. It's not like a camera at all.

Wherever your vision is focused, you'll get a blurring sensation on either side. This is quite apparent during the simple act of reading: you will have a hard time resolving text located just a couple of words either side of the word you're currently focused on.

"Peripheral vision" is more of a "sensation" than actual visual acuity.

You're talking about something different that my remark, but it's a good topic for conversation and you cover some very good points.

I'm talking about "field of vision" which encompasses peripheral vision. The focal area, which would be restricted to the almost tunnel-vision sized area we can focus on at a given time (what you're describing), is indeed a very small area. In conversations about cinema, the phrase "field of vision" is often used to refer to the whole range of visual stimuls coming into the eye from the motion picture including content that may only be perceived via peripheral vision. In fact, that's the whole *goal* of wide-angle viewing and cinema: to fill your peripheral vision and *not* just your focal area.

The 30 degree viewing angle is what begins to fill that peripheral vision to stimulate the brain in ways that just limiting the visual area to your focal area won't do. That's what makes the difference between "waching TV" and "watching a movie". Lots of studies and papers on this and how the brain processes the information very differently which also produces different emotional responses to the same objective image. Obviously, if you're too close to the screen, then you begin to get "tennis head" having to constanly look back/forth to find the area of interest. This is why the 30 degree viewing angle is often quoted as ideal: you're getting peripheral vision stimulation but still comfortably able to move your eyes to follow the action without it becoming a chore.

Your eye also uses the average light hitting your retina to gauge how to adapt to dark/bright... not just what is in your narrow focal area. Otherwise, this whole ambient-light conversation would have no meaning. By using an image that fills your field of vision (including peripheral vision) on its own, you no longer need ambient light as a substitute to average out those levels on your retina to keep you eyes from becoming strained.

1080p and lossless audio. EVERY BD should have them both.
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post #127 of 129 Old 02-26-2010, 01:12 PM
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Quote:
Originally Posted by DaViD Boulet View Post

The 30 degree viewing angle is what begins to fill that peripheral vision to stimulate the brain in ways that just limiting the visual area to your focal area won't do. That's what makes the difference between "waching TV" and "watching a movie". Lots of studies and papers on this and how the brain processes the information very differently which also produces different emotional responses to the same objective image. Obviously, if you're too close to the screen, then you begin to get "tennis head" having to constanly look back/forth to find the area of interest. This is why the 30 degree viewing angle is often quoted as ideal: you're getting peripheral vision stimulation but still comfortably able to move your eyes to follow the action without it becoming a chore.

Your eye also uses the average light hitting your retina to gauge how to adapt to dark/bright... not just what is in your narrow focal area. Otherwise, this whole ambient-light conversation would have no meaning. By using an image that fills your field of vision (including peripheral vision) on its own, you no longer need ambient light as a substitute to average out those levels on your retina to keep you eyes from becoming strained.

This assertion is contrary to current professional practice. See: Rec. ITU-R BT.710-4 'Subjective Assessment Methods For Image Quality In High-Definition Television'- which specifies ambient illumination to be approximately 15% of peak display luminance, at a viewing distance of three screen heights (approx. 30 degree viewing angle), with peak luminance on the screen between 150-250 cd/m2 (44-73 fL).
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post #128 of 129 Old 02-26-2010, 01:28 PM
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Quote:
Originally Posted by GeorgeAB View Post

This assertion is contrary to current professional practice. See: Rec. ITU-R BT.710-4 'Subjective Assessment Methods For Image Quality In High-Definition Television'- which specifies ambient illumination to be approximately 15% of peak display luminance, at a viewing distance of three screen heights (approx. 30 degree viewing angle), with peak luminance on the screen between 150-250 cd/m2 (44-73 fL).

My comments are probably better put in the context of front projection systems, which tend to be less bright than direct-view displays and so ones eyes adjust for the lower average light levels and remain unstrained without ambient light.

Perhaps with a much brighter direct-view display, eyewear is lessened with ambient light.

I can believe that because when I briefly had an Epson projector in my system, which was very bright for a FP unit, I noticed some eye strain and had to turn down the brightness. With ambient light, one could have maintained that high-brightness comfortably.

1080p and lossless audio. EVERY BD should have them both.
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post #129 of 129 Old 02-27-2010, 03:53 PM
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My two cents:

1. Regarding TV: I'm still content with my 4:3 CRT for "TV". Perhaps I'll see demonstrations of 3D-TV products that will change that perspective. But I doubt that it will happen. At some point, I'll need a new TV, and then 3D will be standard. Or perhaps history?

2. Regarding 3D at the movie theater: I think I've seen four films in 3D. First, House of Wax in the 1950s. Then, an IMAX film perhaps 10 or 15 years ago, While it was effective, I felt that that 3D was a gimmick and had no interest in returning (for 3D).

I went to see Monster House (from RealD DLP) in 2006 to check out the technology which I felt was quite good. No desire to go back to see 3D.

I went to see Avatar (from RealD Sony SXRD 4K dual lens) to see if the film and technology lived up to all the hype. It was an enjoyable experience, and quite well done, but still little desire to see more 3D movies. Recently I watched some Avatar clips in 2D and my impression was that it looked quite fake and "layered". I do plan to rent the 2D Blu-ray.

3. Regarding Front Projection at home: The picture from my 720p DLP projector and a Blu-ray disc (at 1.9 screen widths) is very satisfying and at least as good as what I've recently seen from 35mm film projection in the movie theaters. The projector is used for movies and the occasional special TV programs such as the Olympics. I did watch the 3D movie Coraline but only in 2D (which was very good). When it's time for a new lamp, I'll probably buy a 1080p projector, but 3D capability is not likely to be one of my key parameters.

4. Re sports in 3D: I've not seen any sports in 3D and I'm not really a sports person, but I'm mystified has to how well suited this is to 3D. Most of the 3D effects seem work because characters and objects are at quite different distances from the viewer/camera. Many sports are shot with cameras a long distance from the action with superb telephoto zoom lenses. While a dual camera rig could widely separate the lens axes, the players are often about the same distance away. Perhaps boxing might be quite effective in 3D. Ski jumping? I guess I'll have to wait to see demos at the stores...

5. Regarding 3D technology: I find the topic quite interesting. Curious then that I'm not terribly interested in the end result.
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