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8K by 4K or Octo HD - the real SUHDTV technology - Page 9

post #241 of 670
Quote:
Originally Posted by Owen View Post

Any quoted "resolution" that does not specify MTF at that resolution is misleading and tells you nothing.
The graph shows that at 3200 vertical the system has only 20% MTF which is useless, the industry standard is 30% and even that's being generous.
At 30% MTF the camera is only good for about 2200 vertical which is about half 8k for an 8k system. Only very high contrast details have a chance of being visible at 30% MTF, anything less will just be a blur to the eye.
This is an entirely normal and predictable response for an 8k digital camera, the theoretical ideal response is only slightly better and is also shown on the diagram.
MTF tests are done under ideal conditions with everything perfect, real world performance is rarely ever going to be that good. Even slightly imperfect focus due to focus error or depth of field and motion blur result in much less resolution than a perfect still shot under ideal conditions with no motion.

Please provide links that show the "industry standard is 30% MTF."
Edited by Lee Stewart - 9/23/12 at 9:32pm
post #242 of 670
I am not going to waste my time doing research for you, especially since you demonstrate little true interest in the subject and no doubt will want to continue in useless circular argument no matter what I post.
The fact that you even question why using 30% MTF may not be appropriate and even downright lenient tells me you did not read the MTF tutorial I linked, did not understand its implications or simply chose to ignore them.

I posted very practical images that anyone can use to determine what the difference between 4k and 8k will mean to them at their preferred viewing distance without needing to worry about facts and figures, all they had to do was follow the directions provided. For those who simply could not be bothered to do that I have no time.
Edited by Owen - 9/24/12 at 3:59am
post #243 of 670
Quote:
Originally Posted by Owen View Post

I am not going to waste my time doing research for you, especially since you demonstrate little true interest in the subject and no doubt will want to continue in useless circular argument no matter what I post.
The fact that you even question why using 30% MTF may not be appropriate and even downright lenient tells me you did not read the MTF tutorial I linked, did not understand its implications or simply chose to ignore them.
I posted very practical images that anyone can use to determine what the difference between 4k and 8k will mean to them at their preferred viewing distance without needing to worry about facts and figures, all they had to do was follow the directions provided. For those who simply could not be bothered to do that I have no time.

On the contrary, I did do research. Read about a dozen articles/papers on MTF and Spatial Frequency. And not one of them said there was any industry standard of 30% MTF. What they all said was the difficulty of maintainig a reasonablly flat MTF. One even showed how oversampling and down conversion can maintain MTF. Saw lots of %s mentioned, 100%, 50%, 10%, but no 30% industry standard.
post #244 of 670
Quote:
Originally Posted by Owen View Post

The graph shows that at 3200 vertical the system has only 20% MTF which is useless, the industry standard is 30% and even that's being generous.
You have also said that visual acuity calculations were done with "PC generated test patterns with 100% MTF" so there is reason why I would like to see evidence for your statements that 30% MTF is the "industry standard" and "usable minimum".

Quote:
Originally Posted by Owen View Post

The fact that you even question why using 30% MTF may not be appropriate and even downright lenient tells me you did not read the MTF tutorial I linked, did not understand its implications or simply chose to ignore them.
Well in the post where you linked to that website I notice that you said:
Quote:
Originally Posted by Owen View Post

Remember, most details in the real world dont have 100% relative contrast to begin with, 30% is likely more typical. Factor in 50% or more MTF loss and a 30% contrast difference between details in the original image becomes 15% or less in the video which is useless.
It looks like you started out by posting a personal opinion on MTF.
post #245 of 670
Quote:
Originally Posted by Lee Stewart View Post

47015_zps6216c590.png

That might be the most inaccurate chart I have ever seen.

According to it my wife's Apple Cinema Display is horribly deficient. It is a mere 2560x1440 (say, halfway between 1080p and 4k) and it is 27" diagonal and generally viewed from about 2-3'. That chart would suggest that the display is horribly inferior - a 27" display viewed at that distance should be 16k - that is a ~16,000x9,000. That slide is stating that a 3.5 megapixel display is inadequate and that a 144 megapixel display would be most appropriate. The pixels can barely be seen by the user, but the screen should have 40x the pixels? Oh, and the recommended viewing distance for that 27" Cinema Display on that chart is 17'. Whatever....
post #246 of 670
Quote:
Originally Posted by mcnabney View Post

That might be the most inaccurate chart I have ever seen.
According to it my wife's Apple Cinema Display is horribly deficient. It is a mere 2560x1440 (say, halfway between 1080p and 4k) and it is 27" diagonal and generally viewed from about 2-3'. That chart would suggest that the display is horribly inferior - a 27" display viewed at that distance should be 16k - that is a ~16,000x9,000. That slide is stating that a 3.5 megapixel display is inadequate and that a 144 megapixel display would be most appropriate. The pixels can barely be seen by the user, but the screen should have 40x the pixels? Oh, and the recommended viewing distance for that 27" Cinema Display on that chart is 17'. Whatever....

You are not understanding that chart. It is based on 400 pixels per degree. Other charts you have seen are based on 200 pixels per degree or less.
post #247 of 670
With regard to the recent discussions about MTF I provide the following video links.
I suggest you view them in the order below, its gets a bit technical but stay with it and pay attention.
Seminar presented by John Galt (Panavision) and Larry Thorpe (Canon)

http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part3.html
http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part4.html
http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part2.html
http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part1.html


Interesting related link:
http://www.panavision.com/sites/default/files/24P%20Technical%20Seminar%202.pdf

A related interview with John Galt from Panavision can be read here:
http://magazine.creativecow.net/article/the-truth-about-2k-4k-the-future-of-pixels


From the above a few things should become clear.
1. Pixels are not resolution.
2. No digital system can ever have anywhere near the visible resolution its pixel count would indicate due to digital sampling and lens limitations. In fact there is effectively zero response at the pixel level as MTF is 10% or less at the limit of any digital format by design.
3. 8k is far more affected by lens MTF limitations than 4k and lower formats.
4. MTF has a dramatic affect on what “resolution” we can actually see.
5. Super high “resolution” is unimportant for cinema applications, high mid band MTF (well below 2k) dictates visible sharpness.
6. Even IMAX is NOT 4k visible resolution.
7. A system with 30% MTF translates details with 100% relative contrast in the scene (full on / full off) to 30% in the video image, therefore detail with 50% relative contrast in the scene (very typical for real world content) ends up with only 15% relative contrast in the video image, way to blurred to be visible from any reasonable viewing distance.
Edited by Owen - 9/25/12 at 5:16am
post #248 of 670
Thread Starter 
OK guys, this MTF discussion is getting surreal, For Octo HD the camera resolution is not of prirmary importance as one can pump pure computer-generated content. Even the visible resolution per se is not the main factor for the Octo HD. The reason for Octo HD is that it provides healthy resolution headroom to become end-of-the-road system for video applications. While this has been said even in the context of Quad HD and 4K digital cinema, with the headroom provided by the Octo HD no one will be ever able to claim the need for still higher resolution.
post #249 of 670
Cant disagree, 8k is over the top, there should be no need to ever go higher. The real question is whether its appropriate in a bandwidth starved world.

Until bandwidth becomes a non issue 4k with high frame rates and 10bit 4:4:4 color is a far better option than 8k IMHO.
post #250 of 670
Quote:
Originally Posted by Owen View Post

Cant disagree, 8k is over the top, there should be no need to ever go higher.
There will be if "TV" becomes more than a single flat rectangular 2D image like current TVs.
post #251 of 670
Quote:
Originally Posted by Owen View Post

With regard to the recent discussions about MTF I provide the following video links.
I suggest you view them in the order below, its gets a bit technical but stay with it and pay attention.
Seminar presented by John Galt (Panavision) and Larry Thorpe (Canon)
http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part3.html
http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part4.html
http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part2.html
http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part1.html

If interested , here is the rest of the presentation:

http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part5.html
http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part6.html
http://www.freshdv.com/2008/05/demystifying-digital-camera-specs-part7.html

Very enlightening Owen. Thanks for the links.
post #252 of 670
Quote:
Originally Posted by irkuck View Post

OK guys, this MTF discussion is getting surreal, For Octo HD the camera resolution is not of prirmary importance as one can pump pure computer-generated content.

I disagree. The cameras and lenses will be very important. Think of how much video we watch that consists of capturing live subjects; sports, television shows, movies, etc.
Quote:
Even the visible resolution per se is not the main factor for the Octo HD. The reason for Octo HD is that it provides healthy resolution headroom to become end-of-the-road system for video applications. While this has been said even in the context of Quad HD and 4K digital cinema, with the headroom provided by the Octo HD no one will be ever able to claim the need for still higher resolution.
Quote:
Originally Posted by Owen View Post

Cant disagree, 8k is over the top, there should be no need to ever go higher.

Do you really believe that in the year 2150 there will be no higher resolution than 8K? I don't.
post #253 of 670
Quote:
Originally Posted by Lee Stewart View Post

Do you really believe that in the year 2150 there will be no higher resolution than 8K? I don't.
If we're talking about standard displays we use today - resolution increase will stop once we get to the point where display meets visual limitations at viewing distance of few inches. Imagine 100'' display with something like 600 pixels per inch. Mind blown.

But maybe TV then won't be what TV is today, so above example will most likely never come true.

Guys, before you crucify me, remember - I'm talking about distant future where bandwidth and computation power needed for this kind of thing is not a problem at all.
post #254 of 670
Quote:
Originally Posted by mcnabney View Post


That might be the most inaccurate chart I have ever seen.
According to it my wife's Apple Cinema Display is horribly deficient. It is a mere 2560x1440 (say, halfway between 1080p and 4k) and it is 27" diagonal and generally viewed from about 2-3'. That chart would suggest that the display is horribly inferior - a 27" display viewed at that distance should be 16k - that is a ~16,000x9,000. That slide is stating that a 3.5 megapixel display is inadequate and that a 144 megapixel display would be most appropriate. The pixels can barely be seen by the user, but the screen should have 40x the pixels? Oh, and the recommended viewing distance for that 27" Cinema Display on that chart is 17'. Whatever....


I certainly agree that this chart is worthless for practical considerations.    I find Carlton Bale's chart very much spot on from my experience of varying seating distances (from my present 12 ft wide screen and Sony 1000ES projector).

post #255 of 670
Quote:
Originally Posted by Randomoneh View Post

If we're talking about standard displays we use today - resolution increase will stop once we get to the point where display meets visual limitations at viewing distance of few inches. Imagine 100'' display with something like 600 pixels per inch. Mind blown.
But maybe TV then won't be what TV is today, so above example will most likely never come true.
Guys, before you crucify me, remember - I'm talking about distant future where bandwidth and computation power needed for this kind of thing is not a problem at all.

8K = 33 Megapixels . . .

How many megapixels equivalent does the eye have?
Quote:
The eye is not a single frame snapshot camera. It is more like a video stream. The eye moves rapidly in small angular amounts and continually updates the image in one's brain to "paint" the detail. We also have two eyes, and our brains combine the signals to increase the resolution further. We also typically move our eyes around the scene to gather more information. Because of these factors, the eye plus brain assembles a higher resolution image than possible with the number of photoreceptors in the retina. So the megapixel equivalent numbers below refer to the spatial detail in an image that would be required to show what the human eye could see when you view a scene.

Based on the above data for the resolution of the human eye, let's try a "small" example first. Consider a view in front of you that is 90 degrees by 90 degrees, like looking through an open window at a scene. The number of pixels would be
90 degrees * 60 arc-minutes/degree * 1/0.3 * 90 * 60 * 1/0.3 = 324,000,000 pixels (324 megapixels).
At any one moment, you actually do not perceive that many pixels, but your eye moves around the scene to see all the detail you want. But the human eye really sees a larger field of view, close to 180 degrees. Let's be conservative and use 120 degrees for the field of view. Then we would see
120 * 120 * 60 * 60 / (0.3 * 0.3) = 576 megapixels.
The full angle of human vision would require even more megapixels. This kind of image detail requires A large format camera to record.

http://www.clarkvision.com/articles/eye-resolution.html
post #256 of 670
The pertinence of the Carlton Bale chart (link) would seem to be that--at 60 pixels per degree--it is congruent with the NHK "recommended" screen size|resolution|viewing distance guidelines, which are (I believe) likely to be the basis for further ITU Recommendations...?! If that turns out to be case, they will presumably be the 'starting point' for longer term CEM and content provider decisions about which (consumer) screen sizes are best served by 4K2K vs 8K4K resolutions, and whether there will be a large enough segment of the consumer market viewing 8K4K displays from 'close enough' to make mass marketing of 8K4K recorded movie content profitable. (My guess, starting from the NHK-Carlton Bale numbers, is that you probably have to sit 'somewhat closer' to an 8K4K display than about 125% of screen height in order for 8K4K consumer disk source content to appear qualitatively superior to 4K2K consumer disk source material upconverted to 8K4K.)
_
Edited by SoundChex - 9/25/12 at 11:50am
post #257 of 670
Quote:
Originally Posted by SoundChex View Post

The pertinence of the Carlton Bale chart (link) would seem to be that--at 60 pixels per degree--it is congruent with the NHK "recommended" screen size|resolution|viewing distance guidelines, which are (I believe) likely to be the basis for further ITU Recommendations...?! If that turns out to be case, they will presumably be the 'starting point' for longer term CEM and content provider decisions about which (consumer) screen sizes are best served by 4K2K vs 8K4K resolutions, and whether there will be a large enough segment of the consumer market viewing 8K4K displays from 'close enough' to make mass marketing of 8K4K recorded movie content profitable. (My guess, starting from the NHK-Carlton Bale numbers, is that you probably have to sit 'somewhat closer' to an 8K4K display than about 125% of screen height in order for 8K4K consumer disk source content to appear qualitatively superior to 4K2K consumer disk source material upconverted to 8K4K.)
_


My experience is strictly that of an enthusiastic HT guy who likes to sit very close (by most standards) for a very immersive pic.    I currently sit ~ 11 ft from a 11.3x6 ft screen (thus ~ 1 SW, or ~1.78 PH, for 16x9) with Sony's  'consumer 4K' projector, the VW1000ES.  This is about as close as most persons with projectors now sit (and much closer than most), and it is also approximately the distance at which Carlton Bale's chart says the one has 'the full benefit of 4K'.    I have experimented with sitting even closer--e.g., at 6 ft (1 PH)--and find that even I find it too unpleasant; not because the picture is not good, but just because it's not possible (for me) to take it in.

 

From all the discussions here, I thus conclude that 8K doesn't have much to offer for a home viewing situation, but that 4K would be appreciated by many.    So the advent of good 4K source material seems to me to be the most important next step.

post #258 of 670
Quote:
Originally Posted by Lee Stewart View Post

8K = 33 Megapixels . . .
How many megapixels equivalent does the eye have?
http://www.clarkvision.com/articles/eye-resolution.html
Yeah, great article, we've been talking about that before. For displays, results are slightly different (how different depends on angle). I'll be glad to explain in detail if you don't understand what I'm talking about.
Quote:
Originally Posted by SoundChex View Post

The pertinence of the Carlton Bale chart (link) would seem to be that--at 60 pixels per degree--it is congruent with the NHK "recommended" screen size|resolution|viewing distance guidelines...
This is from NHK. Lee Stewart had posted it before.
SMPTE-Motion-Imaging-Journal-May-June-2012-p_65-Figure-3_zps6ef785e9.jpg
From this image you can see that they believe there is a benefit from angular resolution even higher than 300 ppd.
NHK claimed that 312 pixels per degree is a limit, then they've said much of the benefit is visible up to about 110-120 pixels per degree.
Their recommended distances (100 degrees viewing angle for 8K) are trade-off between angular resolution (image quality) and immersion.
post #259 of 670
NHK has a new image on their website:
1-1-1-1.gif
Even at 3 image heights (1080p: 56 ppd, 2160p: 113 ppd, 4320p: 226 ppd), there is a noticeable difference between 4K and 8K. How to explain that? If there is no difference between 2K and 4K, why is there a difference between 4K and 8K?
Edited by Randomoneh - 9/25/12 at 12:59pm
post #260 of 670
SMPTE-Motion-Imaging-Journal-May-June-2012-p_65-Figure-3_zps6ef785e9.jpg
Quote:
It shows that a viewer’s “sense of being there” increases as the viewing distance decreases, as might be expected; as the screen occupies more of the visual field, the viewer gets enveloped in the image. It also shows that “sense of realness” increases with greater viewing distance. That’s also as might be expected; from the top of a skyscraper, a viewer can’t tell the difference between a mannequin (fake) and a person (real) at street level.
post #261 of 670
Quote:
Originally Posted by Lee Stewart View Post

...
Why the hell NHK contradicts itself? Image you posted clearly shows that sense of realness increases with greater viewing distance (screen occupies less of FOV - better sense of realness). New image (that I've posted) shows that sense of realness falls after 1.5 image heights, even though angular resolution is getting higher and higher.

Only reason I can think of for why sense of realness falls off after 3 image heights is because immersion (sense of being there) falls at the same time.
post #262 of 670
Quote:
Originally Posted by Randomoneh View Post

NHK has a new image on their website:
1-1-1-1.gif
Even at 3 image heights (1080p: 56 ppd, 2160p: 113 ppd, 4320p: 226 ppd), there is a noticeable difference between 4K and 8K. How to explain that? If there is no difference between 2K and 4K, why is there a difference between 4K and 8K?

Could it be the difference between 2MP and 8.3MP versus 8.3MP and 33MP at 3 picture height distance?
Edited by Lee Stewart - 9/25/12 at 2:24pm
post #263 of 670
Quote:
Originally Posted by Randomoneh View Post

NHK has a new image on their website:
1-1-1-1.gif
Even at 3 image heights (1080p: 56 ppd, 2160p: 113 ppd, 4320p: 226 ppd), there is a noticeable difference between 4K and 8K. How to explain that? If there is no difference between 2K and 4K, why is there a difference between 4K and 8K?

These are experimental results, and unfortunately, as the printed research paper is (apparently) currently still only available in Japanese, we don't know (amongst many other things!) the sample sizes, confidence intervals, significance of score differences, or researcher interpretations and conclusions. cool.gif
Quote:
[References] (1) Y. Kusakabe, K. Masaoka, I. Kondo, Y. Nishida and M. Sugawara: “Subjective Evaluations of Preferred Viewing Distance and Psychophysical Effects of Extremely High Resolution Images Using Super Hi-Vision 85-inch LCD,” ITE Technical Report, Vol. 36, No. 9, ME2012-62, HI2012-24, AIT2012-24, pp. 245-250 (2012) (in Japanese)


More interesting is the paper's conclusion: "[Using an] 85-inch SHV full-resolution direct-view LCD in a home viewing environment. The experiments using video with three levels of spatial resolution (2K:1920x1080, 4K:3840x2160, 8K:7680x4320) showed that the preferred viewing distance did not depend on the resolution or content and ranged from 1.5 to 4 times the screen height, with the most preferred distance being 2.5 times the screen height." This info might help CEMs choose likely model sizes for future displays.
_
Edited by SoundChex - 9/25/12 at 2:35pm
post #264 of 670
Important: these new tests were done with motion video (unlike last one). Tested resolutions were 1920x1080 (not 2048x1080 as "2K" suggests), 3840x2160 and 7680x4320.

Most important thing:
Quote:
The experiments (...) showed that the preferred viewing distance did not depend on the resolution or content and ranged from 1.5 to 4 times the screen height, with the most preferred distance being 2.5 times the screen height.
Quote:
Originally Posted by Lee Stewart View Post

Could it be the difference between 2MP and 8.3MP versus 8.3MP and 33MP at 3 picture height distance?
Yeah, but conventional wisdom is that, if there is no visible difference between 2MP and 8.3MP, there won't be any visible difference between 8.3MP and 33MP. Obviously there is.
post #265 of 670
2012-02-21 15:40

Subjective evaluation of preferred viewing distance and psyhcophysical effects of extremely high resolution images using Super Hi-Vision 85-inch LCD

"We are currently researching a next-generation broadcasting system named Super Hi-Vision, which has 16 times higher image resolution than that of a high definition television. Using our newly developed 85-inch
liquid crystal display (LCD) for Super Hi-Vision, we performed subjective evaluations to quantify the preferred viewing distance and psychophysical effects of the sense of being there and sense of realness. The results of the first experiment indicate that the preferred viewing distance is 2.5H (H is picture height) on the average and is distributed between 1.5H and 4H regardless of resolution and content. The results of the second experiment indicate that the sense of being there and the sense of realness improve as the image resolution increases when viewing at less than 3H."

http://www.ite.or.jp/ken/paper/201202211ACn/eng/

1-1-1-1.gif
post #266 of 670
So preferred viewing distance was in the range of 25 - 61 degrees (horizontally), regardless of the resolution. This is exactly what I have claimed in one of the other threads: we choose sitting distance not by angular resolution, but by immersion. Angular resolution is only a bonus.

Interesting thing: If they have used 1080p 85-inch TV (instead of simulating 1080p on 4320p set), pixel grid would be even more visible, making the difference between those even higher.
post #267 of 670
NHK also now says that the recommended FOV is 80 - 100 degrees (not just 100) and recommended seating distance (optomim) is between .75 PH and 1 PH (not just .75)
post #268 of 670
Quote:
Originally Posted by Lee Stewart View Post

NHK also now says that the recommended FOV is 80 - 100 degrees (not just 100) and recommended seating distance (optimum) is between .75 PH and 1 PH (not just .75)
Thanks. I don't understand why their recommended seating distance is .75 - 1 image height if the most close preferred seating distance is 1 image height.
Edited by Randomoneh - 9/25/12 at 3:22pm
post #269 of 670
Quote:
Originally Posted by Lee Stewart View Post

NHK also now says that the recommended FOV is 80 - 100 degrees (not just 100) and recommended seating distance (optomim) is between .75 PH and 1 PH (not just .75)

Of course that's still only the difference between sitting with your head six feet or eight feet away from a 200" screen.
post #270 of 670
According to NHK's research, the Sense of Realness (spatial resolution/angular resolution)/visual fidelity, determines whether viewers can distingush images from real objects. The higher the angular resolution, the greater the sense of realness and the sense saturates above about 60 cpd (cycles per degree).

Average visual acuity is about 120 pixels per degree or 60 cycles per degree
Edited by Lee Stewart - 9/25/12 at 3:21pm
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