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post #1 of 99 Old 06-20-2015, 10:19 AM - Thread Starter
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Top 10 Things You Need to Know About Aspect Ratio, Screen Size, and Seating Distance



Aspect ratio, screen size, and seating distance are all important to keep in mind when planning or upgrading your home-theater sanctuary.

1. The aspect ratio of a screen or image is the ratio of its width to its height. Almost all flat-panel TVs, home-theater projectors, and HDTV content have a native aspect ratio of 16:9, aka 1.78:1, while most movies are wider with a native aspect ratio of 1.85:1 or 2.39:1. A few flat-panel TVs have a native aspect ratio of 21:9, aka 2.33:1.

2. If you watch both movies and TV shows, the aspect ratio of the image and screen won't always match; when they don't, you will see black bars above and below or to the sides of the image, as shown above.

3. With flat panels, this is unavoidable unless you use one of the TV's "zoom" functions, which either distort or crop parts of the image. I don't recommend this; learn to live with the black bars to see the image as the content creator intended.

4. Many projector owners get a 2.39:1 or 2.35:1 screen so that widescreen movies fill the screen without significant black bars.

5. One way for a 16:9 projector to fill a wide screen with a widescreen image is to zoom the lens so the active image area fills the screen. Some projectors have several "lens memories" that let you store and recall the zoom, focus, and lens-shift settings for content with different aspect ratios.

6. The other way for a 16:9 projector to fill a wide screen with a widescreen image is to use an anamorphic lens, which optically stretches the image horizontally while the projector electronically upscales the image vertically. For 16:9 content, the anamorphic lens can be moved out of the way, or in the case of a fixed lens, the projector can electronically scale the image to the correct aspect ratio. This approach is more expensive than zooming, but it uses all the projector's pixels, giving the image more resolution and making it brighter.

7. There are various formulas to calculate the optimum seating distance; for the purpose of this list, I will use the ITU (International Telecommunications Union) recommendation of 3 times the screen height for HD and 1.5 times the screen height for UHD/4K, regardless of the screen's aspect ratio.

8. The size of virtually all display screens is specified by their diagonal measurement. For 16:9 screens, the height is about half the diagonal measurement; for 2.39:1 screens, the height is about 0.4 times the diagonal measurement.

9. If you know your screen size, you can calculate the optimum seating distance:

(seating distance) = 3 x (screen height)

For example, a 16:9 screen measuring 70 inches diagonally has a height of about 35 inches, so the optimum seating distance for HD is 105 inches or 8.75 feet; for UHD/4K images, the optimum seating distance is 52.5 inches or 4.4 feet. These seating distances are the same for a 2.39:1 screen measuring 88 inches diagonally, because the height of the screen is still 35 inches.

10. If you know your seating distance, you can calculate the optimum screen size you will need:

(screen height) = (seating distance)/3

For example, if your seating distance is 10 feet (120 inches), the screen height for HD should be 40 inches, which translates to a diagonal measurement of 80 inches for 16:9 or 100 inches for 2.39:1. For UHD/4K, the screen height should be 80 inches, which translates to a diagonal measurement of 160 inches for 16:9 or 200 inches for 2.39:1.

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post #2 of 99 Old 06-20-2015, 10:45 AM
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post #3 of 99 Old 06-20-2015, 10:56 AM
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Quote:
Originally Posted by Scott Wilkinson View Post
10. If you know your seating distance, you can calculate the optimum screen size you will need:

(screen height) = (seating distance)/3

For example, if your seating distance is 10 feet (120 inches), the screen height for HD should be 40 inches, which translates to a diagonal measurement of 80 inches for 16:9 or 100 inches for 2.39:1. For UHD/4K, the screen height should be 80 inches, which translates to a diagonal measurement of 160 inches for 16:9 or 200 inches for 2.39:1.
200" Scope for 10ft seating distance = Win!

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post #4 of 99 Old 06-20-2015, 11:09 AM
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I wonder how many people sit 4.4 feet from a 70" UHD TV? ...Can the brightness of the screen affect your eyes over time?

For example; I sit 18 inches from my 15" screen laptop, and I know that my eyes get tired over time.

Back in the 50s-60s they were telling us to not sit close to our tube TVs; remember...our parents were telling us while playing on the carpet floor of the living room?
And I remember the couch being about 12 feet from a 25" tube cathode TV.

Today we have smart phones with a 6-7" screen size or a tablet with a 10-12" screen size and we sit about 6 inches from it...from the recommendations we should sit much closer.
The screen brightness of our cell phones is getting right inside our eye's retinas and the radio micro-waves right in our brain.
I'm sure all for the best, as compared to the 50s.

Now UHD is here, and even in our laptops (12 to 17" screen sizes), and OLED and LED in the 55 to 75" sizes and we can sit only few inches from them for best imprint on our eyes...details.

I'm invited to my neighbor's house to watch a UHD movie on Blu-ray ('Fury Road: Max Unchained'); we sit down, the screen is 105" diagonal, and our chairs are 6.6 feet from it.
...Times they are a changin'.
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post #5 of 99 Old 06-20-2015, 11:20 AM
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So How close to sit from a 55" tv udhd and hd ? In mestric ?
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post #6 of 99 Old 06-20-2015, 11:37 AM
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Quote:
Originally Posted by Scott Wilkinson View Post
7. There are various formulas to calculate the optimum seating distance; for the purpose of this list, I will use the ITU (International Telecommunications Union) recommendation of 3 times the screen height for HD and 1.5 times the screen height for UHD/4K, regardless of the screen's aspect ratio.
I thought seating-distance-to-screen-height ratio's purpose was to give a correct perspective, since a flat image will look too steep at the sides when seen too close. 1.5 times is too big for a flat image.
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post #7 of 99 Old 06-20-2015, 11:59 AM
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I wouldn't want to sit so close that I get sick following motion across the screen. I am 9.5 ft. from the screen of my 50" Kuro and am not bothered by that distance, though at times I could see having another 5" of screen. Because the back wall is right behind my head I may move the couch a few inches forward, but that's it. Placement options are very limited in this apartment.

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post #8 of 99 Old 06-20-2015, 12:01 PM
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Quote:
Originally Posted by Scott Wilkinson View Post
7. There are various formulas to calculate the optimum seating distance; for the purpose of this list, I will use the ITU (International Telecommunications Union) recommendation of 3 times the screen height for HD and 1.5 times the screen height for UHD/4K, regardless of the screen's aspect ratio.

8. The size of virtually all display screens is specified by their diagonal measurement. For 16:9 screens, the height is about half the diagonal measurement; for 2.39:1 screens, the height is about 0.4 times the diagonal measurement.

9. If you know your screen size, you can calculate the optimum seating distance:

(seating distance) = 3 x (screen height)
That is a good starting point and documents like those from CEDIAs CEB23 or SMPTE for example suggest that; with a range of plus or minus one screen height (3x +or- 1x), so a range of 2 x SH to 4 x SH. 2xSH is where SMPTE recommend the closest seating distance should be, 4x the furthest.

Three times SH was also the Fox recommendation for film based on the crossover point where immersion (closer is better) and image quality (further means less arifacts) cross over.

However, THX looked at film stock and decided that 2.4 x the SH was the optimal viewing distance (3.68 xSH recommended for the back row), and it still is for HD. With a 2.35 screen, when viewed from the same seat/viewing distance, 16:9 will give you a 40 degree viewing angle and 2.35 around 52 degrees. Ideally you will be using an anamorphic lens to keep the vertical resolution the same, but image quality can depend on the tech being used (DLP, DiLA etc) and set up (reflectance level and calibration), so zooming can still be OK at closer seating distances. Or use a 4k display with good scaling for HD or 4k source material.

If the original design intent is important to you, scope should be the largest/widest aspect ratio (other than IMAX), with all others shown at the same height within it, in a constant image height presentation method.

With Sony's recommendation of 1.5 x SH for 4k/UHD, you should be aware that at that distance ratio, you may want to set your seating so that your eyes fall at around the center vertical or higher so that vertical viewing angles don't exceed the max recommended 35 degrees for comfort.

Gary

Quote:
Originally Posted by elmalloc
Who says Cameron is "right" and why do we care about him so much - lol!

I trust Gary Lightfoot more than James Cameron.

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post #9 of 99 Old 06-20-2015, 02:15 PM
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Quote:
Originally Posted by NorthSky View Post
I wonder how many people sit 4.4 feet from a 70" UHD TV? ...Can the brightness of the screen affect your eyes over time?

For example; I sit 18 inches from my 15" screen laptop, and I know that my eyes get tired over time.

Back in the 50s-60s they were telling us to not sit close to our tube TVs; remember...our parents were telling us while playing on the carpet floor of the living room?
And I remember the couch being about 12 feet from a 25" tube cathode TV.

Today we have smart phones with a 6-7" screen size or a tablet with a 10-12" screen size and we sit about 6 inches from it...from the recommendations we should sit much closer.
The screen brightness of our cell phones is getting right inside our eye's retinas and the radio micro-waves right in our brain.
I'm sure all for the best, as compared to the 50s.

Now UHD is here, and even in our laptops (12 to 17" screen sizes), and OLED and LED in the 55 to 75" sizes and we can sit only few inches from them for best imprint on our eyes...details.

I'm invited to my neighbor's house to watch a UHD movie on Blu-ray ('Fury Road: Max Unchained'); we sit down, the screen is 105" diagonal, and our chairs are 6.6 feet from it.
...Times they are a changin'.
These are interesting points. There is a lot of research being done on Blue Light that is emitted by smart phones, tablets and televisions. It is very close to UV light on the wavelength spectrum and is being concluded that it causes eye strain and possible negative effects to the health of the eyes.
As far as viewing distance there is a point at which eye strain will be an issue. Basically anything closer than 20 ft will demand the eyes to consistently focus to keep the image clear. This will bring about eye strain over time. In my professional opinion I always suggest sitting at least 8 ft away from the television.

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With direct view displays (tvs, not projected images that are usually much larger), bias lighting can help prevent eyestrain.

Gary

Quote:
Originally Posted by elmalloc
Who says Cameron is "right" and why do we care about him so much - lol!

I trust Gary Lightfoot more than James Cameron.
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post #11 of 99 Old 06-20-2015, 02:58 PM
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I've been telling my wife I need to replace my 55 inch with a 80 inch TV.
Now if I can only get her to read this article and agree.
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post #12 of 99 Old 06-20-2015, 03:07 PM
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I think most people aren't worrying about the scientific method of where to sit. They just pick their spot, no matter where. If it's too close or too far away, they'll just re-position themselves to where they are most comfortable, and enjoy watching. (Like Sheldon on Big Bang Theory - now there's a guy that does it the scientific way!)

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post #13 of 99 Old 06-20-2015, 03:24 PM
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Quote:
Originally Posted by Scott Wilkinson View Post
...

3. ... learn to live with the black bars to see the image as the content creator intended.

...
The very reason I avoided pan and scan movies. AND the reason I got a projector. Watching letterboxed movies on a 34" 4x3 just didn't cut it!
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post #14 of 99 Old 06-20-2015, 03:55 PM - Thread Starter
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Quote:
Originally Posted by Gary Lightfoot View Post
With direct view displays (tvs, not projected images that are usually much larger), bias lighting can help prevent eyestrain.

Gary
Yep, that will be in my next top 10 list about the visual environment.
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post #15 of 99 Old 06-20-2015, 03:56 PM
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Quote:
Originally Posted by DrMichael View Post
These are interesting points. There is a lot of research being done on Blue Light that is emitted by smart phones, tablets and televisions. It is very close to UV light on the wavelength spectrum and is being concluded that it causes eye strain and possible negative effects to the health of the eyes.
As far as viewing distance there is a point at which eye strain will be an issue. Basically anything closer than 20 ft will demand the eyes to consistently focus to keep the image clear. This will bring about eye strain over time. In my professional opinion I always suggest sitting at least 8 ft away from the television.
The blue light hazard is not a simple catchall that encompasses all ranges of blue light. The main concern is with very short wavelength blue/near-violet in the neighborhood of 430 nm and below. If you look at Rec 2020 its blue is 467 nm, and you get plenty of that in natural daylight. Maybe some products use LEDs where there is more energy in the short wavelengths? At any rate, I agree you shouldn't sit in front of any display for hours on end without giving your eyes an opportunity for some rest, especially not that close.
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post #16 of 99 Old 06-20-2015, 04:42 PM
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Quote:
Originally Posted by Gary Lightfoot View Post
That is a good starting point and documents like thse from CEDIAs CEB23 or SMPTE for example suggest that; with a range of plus or minus one screen height, so a range of 1 x SH to 4 x SH. 2xSH is where SMPTE recommend the closest seating distance should be.

Three times SH was also the Fox recommendation for film based on the crossover point where immersion (closer is better) and image quality (further means less arifacts) cross over.

However, THX looked at film stock and decided that 2.4 x the SH was the optimal viewing distance (3.68 xSH recommended for the back row), and it still is for HD. With a 2.35 screen, when viewed from the same seat/viewing distance, 16:9 will give you a 40 degree viewing angle and 2.35 around 52 degrees. Ideally you will be using an anamorphic lens to keep the vertical resolution the same, but image quality can depend on the tech being used (DLP, DiLA etc) and set up (reflectance level and calibration), so zooming can still be OK at closer seating distances. Or use a 4k display with good scaling for HD or 4k source material.

If the original design intent is important to you, scope should be the largest/widest aspect ratio (other than IMAX), with all others shown at the same height within it, in a constant image height presentation method.

With Sony's recommendation of 1.5 x SH for 4k/UHD, you should be aware that at that distance ratio, you may want to set your seating so that your eyes fall at around the center vertical or higher so that vertical viewing angles don't exceed the max recommended 35 degrees for comfort.
It seems to me that we're mixing up the rationales for distance. In the past, the ratios have been different depending on resolution of the content/display .. ie. SD vs HD. But I thought the 40 degree recommendation (or 36) was largely determined by our field of vision and/or by the limits of 'immersion'. If that's the case, then the optimum distance should be independent of the resolution. With UHD and the 1.5 SH recommendation, I haven't done the math but it seems to me that you'd be violating the 36/40 degree viewing angle recommendation.
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post #17 of 99 Old 06-20-2015, 04:47 PM
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I have a 120" 16:9 1080p screen and sit 9-10ft away and that feels perfect for me

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Quote:
Originally Posted by vaktmestern View Post
So How close to sit from a 55" tv udhd and hd ? In mestric ?
2.3 meters for HD and 1.1 meters for UHD.
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I think it should be mentioned that screen size does not matter, it really just shifts your seating distance. Everything takes a certain amount of space in your vision (called field of view) and regardless of the TV size or projector throw in the end if you sit at the recommended viewing distance that screen will take exactly the same amount of space in your vision regardless of the TV screen size. (This is because all TV's have a fixed resolution, so if you sit at the exact perfect acuity for the pixels, it ends up being the same field of view. This is why with virtual reality, you can get an experience equivalent to a 90+ inch TV because its so close to your eyes.)


So basically, a 28 inch screen at 2 feet is equivalent to a 120 inch screen at 8 feet.

Some people prefer sitting further away than really close, but if you can make a choice of sitting 1 feet closer to save several thousands of dollars (55 inch 4k vs 65 inch 4k depending on the screen technology) then it's worth mentioning this.

Quote:
Originally Posted by IanR View Post
It seems to me that we're mixing up the rationales for distance. In the past, the ratios have been different depending on resolution of the content/display .. ie. SD vs HD. But I thought the 40 degree recommendation (or 36) was largely determined by our field of vision and/or by the limits of 'immersion'. If that's the case, then the optimum distance should be independent of the resolution. With UHD and the 1.5 SH recommendation, I haven't done the math but it seems to me that you'd be violating the 36/40 degree viewing angle recommendation.
You are correct, the whole 30-40 degree field of view was designed specifically because our eyes are actually not that great at resolving detail beyond 40 degrees. This is precisely why when you go to a movie, while the movie in the theater is at 4k you may have notice your TV at home at 1080p looks sharper, that's only because movies are at 60-90 degrees field of view and 1080p sets are between 30-40 degrees. If you sit closer to your TV, all you're doing is reducing the clarity of your overall vision.



The best resolution for our field of view is actually somewhere around 1440p, or 1660p to be precise; so 4k is still an upgrade but only about 30% or so. Even if they fixed the field of view in 4k, we would still only be able to resolve around 1660p; the fixed field of view would just prevent us from losing overall clarity in the image.

But tread carefully, I have mentioned this many times and people have their own opinions on this. It always ends in a quote battle and fights.

Disclaimer: There is plenty of research on this online. If you want more details on this simply private message me. I don't want this thread to turn into a quote battle because many people are getting simply tired of the ranting against my claim.

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post #21 of 99 Old 06-20-2015, 06:44 PM
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Quote:
Originally Posted by DrMichael View Post
These are interesting points. There is a lot of research being done on Blue Light that is emitted by smart phones, tablets and televisions. It is very close to UV light on the wavelength spectrum and is being concluded that it causes eye strain and possible negative effects to the health of the eyes.
As far as viewing distance there is a point at which eye strain will be an issue. Basically anything closer than 20 ft will demand the eyes to consistently focus to keep the image clear. This will bring about eye strain over time. In my professional opinion I always suggest sitting at least 8 ft away from the television.
I see in your sig that your HDTV is 65" diagonal. ...Eight feet (96") from it is good. ...Even for 3D Blu-rays.
* Mine is 60", and I sit 7.5 feet (90") from it, on average. ...Seven feet minimum and eight feet maximum. ...I feel alright, I feel 3D.

<<♦>> Top one thing you need to know about seating distance: Take good care of your eyes first.
Because they want you to buy big TVs and sit closer to them; good business for the TV industry, bad business for your eyes.
It reminds me back in the 50-60s the advertising for cigarettes. ...Look @ cancer today...we know the story...money first, health last.
And now they keep @ it but with the TVs this time. ...And tomorrow eye's doctors will be in short supply, and lawsuits filling our law courts.

Yup, encourage people to damage their eyesight by corrupted TV advertisers/manufacturers and TV experts with sick recommendations.
We live in a world of vices, non-stop, the capitalist way, and the healthcare system cannot keep up.

What's more important? ...A huge OLED UHD TV, a big UHD front projector, or a good set of eyes to sleep better @ night and be able to see the mountains and eagles flying outside?

Nice thread, with few important points missing. ...Are we blind?

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post #22 of 99 Old 06-20-2015, 08:39 PM
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Thumbs up Use this 20-20-20 rule for eye care!

While looking at display monitors & TV's...Every 20 minutes, look away from the monitor/TV's at anything at least 20 feet (58 meters) away for 20 seconds! I know this may seem unreasonable while watching an intriguing show/movie, but its easier to do than you think. Good habits are just as easy to learn as bad habits are!
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post #23 of 99 Old 06-20-2015, 08:41 PM
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You, an eye doctor?

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post #24 of 99 Old 06-20-2015, 09:23 PM
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Quote:
Originally Posted by Scott Wilkinson View Post


6. The other way for a 16:9 projector to fill a wide screen with a widescreen image is to use an anamorphic lens, which optically stretches the image horizontally while the projector electronically upscales the image vertically. For 16:9 content, the anamorphic lens can be moved out of the way, or in the case of a fixed lens, the projector can electronically scale the image to the correct aspect ratio. This approach is more expensive than zooming, but it uses all the projector's pixels, giving the image more resolution and making it brighter.
i've always had a 'philosophical' issue with this reasoning.

i'm a believer that resolution is really about the SOURCE and not how you manipulate it. just like watching dvd's on my 1080p tv is nowhere near the same as a true 1080p source, the minor upscaling done when using an a-lens is at best insignificant.

sure there's technically more pixels displayed, but there's not going to be more detail in the image. and i'd argue that since it's no longer a 1:1 pixel mapping, you're probably getting less. kind of like how 720p content actually looks better on 720p displays than 1080p ones.

what we really need(ed) was for UHD to be a wider format. i'd love to have native 2.35:1 displays/projectors with a source to match that. now that i've experienced CIH, it's what i want for everything. the director can decide how wide the field of view is, but i want to decide on the height of the screen as that's how i perceive 'size'.
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post #25 of 99 Old 06-20-2015, 09:40 PM
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Originally Posted by NorthSky View Post
I wonder how many people sit 4.4 feet from a 70" UHD TV? ...Can the brightness of the screen affect your eyes over time?

For example; I sit 18 inches from my 15" screen laptop, and I know that my eyes get tired over time.

Back in the 50s-60s they were telling us to not sit close to our tube TVs; remember...our parents were telling us while playing on the carpet floor of the living room?
And I remember the couch being about 12 feet from a 25" tube cathode TV.

Today we have smart phones with a 6-7" screen size or a tablet with a 10-12" screen size and we sit about 6 inches from it...from the recommendations we should sit much closer.
The screen brightness of our cell phones is getting right inside our eye's retinas and the radio micro-waves right in our brain.
I'm sure all for the best, as compared to the 50s.

Now UHD is here, and even in our laptops (12 to 17" screen sizes), and OLED and LED in the 55 to 75" sizes and we can sit only few inches from them for best imprint on our eyes...details.

I'm invited to my neighbor's house to watch a UHD movie on Blu-ray ('Fury Road: Max Unchained'); we sit down, the screen is 105" diagonal, and our chairs are 6.6 feet from it.
...Times they are a changin'.
I love big, but if I sat 6.6 ft from my 106" it would be a miserable experience FOR ME. Your mileage may vary.
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42" in the dining room.50" in the bedroom 80" in the living room 65" in the family room 70" in the family room 106" in the family room "There is another system" Video Modes: SDTV-EDTV-XGA-HDTV-4K
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post #26 of 99 Old 06-20-2015, 09:43 PM
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Originally Posted by NorthSky View Post
I see in your sig that your HDTV is 65" diagonal. ...Eight feet (96") from it is good. ...Even for 3D Blu-rays.
* Mine is 60", and I sit 7.5 feet (90") from it, on average. ...Seven feet minimum and eight feet maximum. ...I feel alright, I feel 3D.

<<♦>> Top one thing you need to know about seating distance: Take good care of your eyes first.
Because they want you to buy big TVs and sit closer to them; good business for the TV industry, bad business for your eyes.
It reminds me back in the 50-60s the advertising for cigarettes. ...Look @ cancer today...we know the story...money first, health last.
And now they keep @ it but with the TVs this time. ...And tomorrow eye's doctors will be in short supply, and lawsuits filling our law courts.

Yup, encourage people to damage their eyesight by corrupted TV advertisers/manufacturers and TV experts with sick recommendations.
We live in a world of vices, non-stop, the capitalist way, and the healthcare system cannot keep up.

What's more important? ...A huge OLED UHD TV, a big UHD front projector, or a good set of eyes to sleep better @ night and be able to see the mountains and eagles flying outside?

Nice thread, with few important points missing. ...Are we blind?
While I find some folks sitting distances to be absurdly close, there is not a shred of peer-reviewed evidence to support your nonsense about damaged eyesight.

42" in the dining room.50" in the bedroom 80" in the living room 65" in the family room 70" in the family room 106" in the family room "There is another system" Video Modes: SDTV-EDTV-XGA-HDTV-4K
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post #27 of 99 Old 06-20-2015, 09:59 PM
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Shouldn't there be one more measurement - the relationship of the vertical position of the screen/vertical head angle? A ceiling mounted screen that lowers, you are looking slightly upward, a fixed screen positioned where you are looking straight ahead.
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post #28 of 99 Old 06-20-2015, 10:09 PM
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Honestly, I look at the recommended distances as appropriate for watching TV, not movies. I want to be fully immersed into a film and sitting 3x the height puts me squarely in my second row. It's not bad to be there, but it's not even close to being as immersive as my front row.

The heuristic that works for me is to sit close enough that any closer will make you feel nauseous in quick motion scenes. I find that to be somewhat closer to 2x the height.
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post #29 of 99 Old 06-20-2015, 10:19 PM
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For me, 3x screen height works out about right.

However, for shakeycam (like The Blair Witch Project or Cloverfield), 6x screen height is too close.

On the other hand, when watching 2.35:1 material on the big TV, sometimes I wish for a bigger TV or a decent way to sit closer to the screen, which isn't practical the way my man cave is laid out.

My very humble setup:
Spoiler!
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post #30 of 99 Old 06-20-2015, 10:25 PM
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Quote:
Originally Posted by DrMichael View Post
These are interesting points. There is a lot of research being done on Blue Light that is emitted by smart phones, tablets and televisions. It is very close to UV light on the wavelength spectrum and is being concluded that it causes eye strain and possible negative effects to the health of the eyes.
As far as viewing distance there is a point at which eye strain will be an issue. Basically anything closer than 20 ft will demand the eyes to consistently focus to keep the image clear. This will bring about eye strain over time. In my professional opinion I always suggest sitting at least 8 ft away from the television.
I've not measured UV light using a Jeti 1211 in any modern form of display. UV light is largely scattered by the upper atmosphere ozone layer, although some still gets through. People in the southern hemisphere who's ozone layer has a large hole in it from pollution can get eye damage from long out door exposure over a life time. FWIW if UV-B or C was coming from a display you could be blind in a relatively short space of time. OMG sunbeds!!!!
If someone was concerned all they need to do is wear clear plastic glasses as plastic absorbs a lot of UV light up to 300nm or so. I've tested this in the LAB and spectro which can read down to 190nm.


However a side note, which is related to field of view. The effects of flicker rates is of concern, the flicker filling the field of view and in some cases filling the peripheral viewing area as super wide viewing does can have health problems especially for those who have a sensitivity to flicker, which can be attributed to a vestibular disorder or photosensitive epilepsy. There are degrees to these things where many people don't know they have sensitivity at all.
For these people, the higher the frame rate the better for them, they also can be better off with a smaller screen size ratio and balanced room illumination.


I'm not a health professional, but the above is from medical papers related to this subject where the results lead to health warnings of 50/60hz fluorescent lighting, where now the standard install of this form of lighting is high 10~20000hz ballasts. People mistake the light source wavelengths as the problem, as with displays.


Pay attention to migraines or other eye/head problems that come about after viewing, if they continue seek professional advice.


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