Does 4K Resolution Matter?

4k resolution flat panel televisions, such as the LG 84LM9600 84″ LED LCD, are now available and potential buyers are wondering if the extra resolution is worth it. In some cases it is, but in most, it’s not.  The details below can help you decide.

What Exactly is 4K (and 8K) Resolution?

The previous specification for HDTVs is based on the 1080p standard, which has a resolution of 1920×1080 (2.1 million) pixels. The UHD resolutions are based on multiples of this resolution with the same 16:9 (1.78:1) width-to-height ratio.

4k resolution doubles the number of horizontal and vertical pixels (versus 1080p HD), giving approximately 4 thousand (4k) vertical lines. More specifically, the resolution is 3840×2160 (8.3 million) pixels. In traditional terms, 4k could be called 2160p. This standard is also know as QFHD (Quad Full High Definition, or 4x the resolution of HD 1080p.)

8k resolution gives four times the number of horizontal and vertical pixels vs. 1080p HD, which is approximately 8 thousand (8k) vertical lines. More specifically, the resolution is 7680×4320 (33.2 million) pixels. In traditional terms, 8k could be called 4360p. 8k offers 16 times the resolution of 1080p HD.

The ITU and the Consumer Electronics Association have officially dubbed both 4k and 8k resolution as Ultra High-Definition (but it is sometimes called Ultra HD, or UHD, or UHDTV, or Super Hi-Vision.)  This UHD name technically applies to both 4k and 8k, regardless of which of these resolutions it is.  However, most manufacturers are clarifying the UHD nomenclature by specifying 4k UHD and 8k UHD.

(Side notes: Digital Cinema 4k has a resolution of 4096 x 2160 due to a slightly wider aspect ratio of 1.90:1.  This aspect ratio would not be found in typical consumer products. HDMI 1.4 supports 4k resolutions (both 3840 x 2160 and 4096 x 2160) but is limited to a frame rate of 30 frames per second, so it’s fine for viewing movies filmed at 24 frames per second, but not for 48 frame per second 3D movies or other HFR [60 or 120 frames per second High Frame Rate] material.)

Will I be Able to Notice the Additional Resolution?

To be able to detect the additional resolution of 4k (or 8k), the screen must be quite large enough and you must sit fairly close. So how do you know if your particular setup would benefit?  Here’s your answer.

Based on the resolving ability of the human eye (with 20/20 vision it is possible to resolve 1/60th of a degree of an arc), it is possible to estimate when 4k resolution will become apparent for the average eyeball. Using the Home Theater Calculator spreadsheet as a base, I created a chart showing, for any given screen size, how close you need to sit to be able to detect some or all of the benefits of a higher resolution screen. (Click the picture below for a larger version.)

Resolution vs. Screen Size vs. Viewing Distance Chart

(Note for those of you not used to reading charts: screen size is on the horizontal axis; find your screen size and go straight up until you hit the 4k line.  Follow it to the left. That is your minimum seating distance to fully benefit from 4k resolution.)

What the chart shows is that, for a 84-inch screen, 4k resolution isn’t fully apparent until you are at least 5.5 feet or closer to the screen. For a “tiny” 55-inch screen, you’ll need to be 3.5 feet or closer. Needless to say, most consumers aren’t going to sit close enough to see any of extra resolution 4k offers, much less 8k.

It’s important to note that research by Bernard Lechner (former VP of RCA Laboratories) found that the average viewing distance of American TV viewers to be 9 feet. This is substantially farther than the 5.5 foot distance required to fully resolve normal-sized 4k screens. I don’t see people rearranging their living rooms to take advantage of the otherwise unnoticeable UHD resolution benefits.

Verification of Calculations by Sony and THX

It’s interesting to note that Sony lists identical required viewing distances in the Frequently Asked Questions section of their product description.  Checkout the Amazon.com product description FAQ for the Sony 65X900A 4k Ultra HDTV. It shows the same distances I have calculated (i.e. 3.6 feet for a 55″ screen and 4.2 feet for a 65″ screen.) If you don’t believe my numbers, confirmation from Sony should help convince you.

Quote from Sony FAQ:
How close to the TV must I sit to appreciate 4K?
The short answer is that between 5 and 6 ft. is the ideal viewing distance for a 55” or 65” Sony 4K Ultra HD TV. However, on a 55“, you can now sit as close as 3.6 ft and enjoy a visibly smoother and more detailed picture (e.g you won’t see the individual pixels). On a 65“ TV, you can sit as close as 4.2 ft. to appreciate 4K.
THX also confirms similar viewing distances:
On a 50-inch 1080p HD display, most consumers can begin to distinguish individual pixels only when standing within six feet of the screen. Therefore if your viewing distance is 10 feet or greater, an Ultra HD 50-inch display will likely have little perceived benefit in terms of image clarity and sharpness [source]

The Possible Exception: 1080p 3-D Content on Passive (polarized) Screens

Does anyone actually watch 3-D movies at home? No, not really. 3D at home has pretty much flopped. But if you’re one of the few who does, here’s how you may  benefit:

There may be a benefit if you who watch 3-D 1080P Blu-ray movies. There are two types of 3-D glasses: more expensive Active Shutter glasses and lower-cost Passive Polarized Lens glasses. Active Shutter glasses deliver the full screen resolution to each eye; Polarized Glasses deliver only half the screen resolution to each eye (540 instead of 1080 vertical lines)

4k allows all 1080 lines to be visible when using Passive Polarized glasses. You wouldn’t be able to get the full benefit from 4k 3-D, but 4k content doesn’t really exist yet anyway.

Obviously, this is only relevant if you 1) own a polarized screen 3-D TV (LG is the most prevalent adopter of this technology) and 2) watch 3-D Blu-ray movies. Based on the abysmal adoption rates of 3-D, I don’t see this being much of a selling point for UHD TVs.

Can you even get 4k and 8k Content?

If you are among the rare few who has a giant screen and sits close enough to it to benefit from 4k resolution, you still need UHD content to watch. Good luck finding it. Regardless of screen resolution, the source material needs to have the same resolution as the display to see any real advantage. Video Processors will upscale any input to 4k resolution, but upscaling only offers a marginal improvement. Until true 4k and 8k content is widely available, which is a long way off, you are better off saving your cash and getting a 1080p HD TV instead.

As of this writing, the only readily available content source for 4k is the Sony PlayStation 3, and it can only display static pictures (not moving video) using the HDMI 1.4 connection (which only supports a 24 or 30 Hz refresh rate at 4k resolutions.) This may be worthwhile for photographers, but probably not for anyone else. Sony is also offering a UHD movie server that downloads certain Sony Pictures titles in 4k resolution. Due to the limited amount of content and low adoption rate, this would seem to have only marginal impact in availability of UHD content.

Netflix is offering some material in 4k resolution. I haven’t seen it, so I can’t comment on the quality, but I can say that they stream in real time and that the bit rate is fairly low for a resolution this high. If it’s like their other HD streams, the resolution is OK, but the color banding and color depth are noticeably deficient. Hopefully their 4k streams are of better quality and become more widely available.

In conclusion

The benefits of 4k and 8k are marginal at best. You have to sit unrealistically close to see the full detail and you also need 4k source material, which is virtually non-existent. If you want a 3D TV that uses Passive Polarized Glasses, you will gain the ability to view 1080p content at full resolution. If you want to use a PS3 to view 4k photos, you could benefit from 4k. And if you use it as a computer monitor to view high resolution source material, you could benefit. Other than that, save your cash and purchase 1080p instead. Or better yet, purchase a 1080p OLED TV instead; the near infinite contrast ratio will offer vastly more benefit than would higher resolution.

ISF states the the most important aspects of picture quality are (in order): 1) contrast ratio, 2) color saturation, 3) color accuracy, 4) resolution. Resolution is 4th on the list, so look at other factors first. Also, be sure to calibrate your display! I recommend the following calibration tools.

Recommended Calibration Tools

“Just tell me what resolution HD TV to get”

If you don’t like reading charts and are looking for a quick answer, enter you screen size below to see how close you’ll need to sit to fully appreciate various screen resolutions.

Enter screen size: inches diagonal

  • For 480p (720×480) resolution, you must sit:
    feet or closer for full benefit
  • For 720p (1280×720) resolution, you must sit:
    feet or closer for full benefit
  • For 1080p (1920×1080) resolution, you must sit:
    feet or closer for full benefit
  • For 4k (3840×2160) resolution, you must sit:
    feet or closer for full benefit
  • For 8k (7680×4320) resolution, you must sit:
    feet or closer for full benefit

66 Comments »

  • [...] Does 4K Resolution Matter? | CarltonBale.com. [...]

  • mvakleko says:

    What you are talking about is the micro effect. We should also look at the macro or the effect as a whole. The bottom line is that 4k makes things look a lot more “lifelike”…just look at one yourself side by side and decide. Sales people used to tell us the same thing for 720p on a 32″. which is a bunch of bs!

    • Fred M. says:

      This sounds a lot like the video equivalent to the audiophile BS that I’ve been dealing with for years.

      You want to claim that there’s some “macro” effect that makes it look more “lifelike”? Then do the hard work of proving you can see it in double-blind test. Same thing for 1080P vs. 720P on a 32″ screen.

      And don’t tire me with snooty, self-promoting crap about how you’re an astute viewer with hawk-like vision and the finest source components that money can buy. Similarly, don’t waste my time with deprecating remarks about how I must somehow be inferior, or have inferior equipment to yours, if I don’t immediately agree with your proclamations about “lifelike” video “macro” effects.

      • arc orbis says:

        You are absolutely right. On my first copy of Stereophile, 20 years ago, I cancelled my subsciption because of the endless and nonsensical articles about “bolting down” record and cd players to extract better sound through less vibrations and getting separate amps per speaker and gold plating everything … etc. The HDTV market must be reaching a sales plateau and that’s why they are pushing this ultra HD “snake oil” onto us.

      • dobyblue says:

        And where is your double-blind testing to prove the contrary?

        • Fred Maxwell says:

          Where’s your double-blind testing to prove that I cannot hear 100KHz, see infrared, and feel peas under my mattress? You don’t have any? Then I must be able to do all of those things if I claim that I can, right?

          Learn some basics about science. You don’t just accept, as fact, any random claim that comes your way when there is no evidence provided. It’s up to the person making the claim to substantiate it.

  • [...] Referenced from this article by Carlton Bale [...]

  • [...] Using a screen calculator estimating a 50 foot screen (600 inches), I would have to sit a maximum of 37 feet away (American [...]

  • Hudini says:

    ” … feet or closer for full benefit” is wrong.

    ” … feet or remoter for full benefit” is right.

    • Carlton Bale says:

      No, what is written in the article is correct. For example, if what you stated were true, you could stand 1,000 feet away from a 42-inch display and see the full detail of 4k. Obviously, this is not possible.

      • Hiran W says:

        Depending on ones visual acuity one has the be a specific distance from the screen moving(much) closer will not make the image sharper or more cohesive, there is a +/- distance that needs to be taken into consideration.

        X number of pixels(image data) per degree, moving closer reduces the number of pixels per degree, thus making the image less sharp and reducing image quality. We need specific about that distance. Greater or closer to a point say x % no more or less.

        Saying “or closer” gives the impression one can be right up to the screen and still get the benefit of 1080/2160, which is incorrect and misleading.

        • larokus says:

          Absolutely, I have 20/10 vision and can’t even stand watching a 75 inch or larger 1080p screen at the store from under 12 feet they look like massive horrendous macro-blocking affairs. Bring on native 4k content and screens and be done with all the whining already. We should certainly acknowledge that anyone with vision above 20/20 could notice a drastic improvement from much greater distance.

          • Fred M. says:

            That’s probably because almost all stores pump a 720p, or even 480i, signal to every TV in the store and then blow out all of the details by setting the TV to “Vivid” or “Dynamic” with the contrast and brightness set at 100%.

            I’ve dealt with gifted listeners and viewers — just ask them. I’ve known audiophiles who say that their hearing and listening skills are so good that 192KHz/24 bit audio sounds far better than 96KHz/20-bit audio. They claim to get headaches if they even hear a CD. I’ve talked to videophiles who claim that they have such visual acuity that they can calibrate a monitor without a test disc or measuring equipment. I’ve talked to others who say that they can definitely see an improvement when they switch to gold-plated, $100 HDMI cables (must be the rounder 0s and sharper 1s).

            The problem with such claims is that most are not backed up with double-blind tests. If we take a 4K monitor and position it at a normal viewing distance, can you reliably identify whether there’s a 1920 x 1080 or a 3840 x 2160 signal being displayed on it? I’m not asking if you believe you can — I’m asking if know you can because you’ve shown an ability to do so in such a test.

            It’s all about expectation bias. All humans are subject to it. When people expect a difference, they identify one. If you serve them wine in two glasses, most will express a strong preference for the one you said was more expensive. If you play the same audio recording twice, once identifying it as a “studio master” and the second time identifying it as an MP3 file, most people will be sure that the MP3 file sounds far worse. It’s no different in the world of video.

  • John Hess says:

    Hi Carlton – I want to thank you for this article – It has been very very helpful in shaping my understanding of the relationship between pixels and viewing distance.

  • [...] nhất (ví dụ 4K là vạch tím, 1080 là vạch đỏ …) hay tính toán ở đây : CarltonBale.com – Còn khi ta coi phim giải trí, thì có thể ngồi lùi ra xa một ít, miễn đừng [...]

  • [...] The new Ultra High Definition is beneficial in theaters…. Check out carltonBale.com TV sizes, resolution and viewing distance. [...]

  • 4k and 8k are completely pointless for the home. This is probably yet another money grab by the psycho dogs who rip babies of their candies in their sleep. The corporate whore bags of america. You’re telling us that a resolution that is used in the fucken movie theater where the image is blown up 100x is good for the home where the average screen size is 40″ or so. Suck a tail pipe already.

  • Photo Joe says:

    I don’t have the greatest vision, but I can easily see individual pixels on my 63″ screen from 10′.

    The whole point is you want the pixels so small you CAN’T see them… You are measuring the other way around.

  • Photo Joe says:

    Furthermore — take a look at a good ‘hd’ tablet (one that fits into your “fully benefited” pixels-per-arc-minute calculation) and then look at a 1600×2560 Nexus (which is considerably higher resolution than you say we can benefit from). The Nexus looks considerably sharper.

    • paladinmrb says:

      Prop-up said tablets on a table side by side, stand 10 feet away and tell me which one has a better resolution mmmkay?

      The point is in the DISTANCE from the screen.

      Obviously if I hold an iPad2 with 1024×768 resolution and an iPad4 with a retina display (I forget the pixel density but it’s something in the 2k realm) about a foot from my face the iPad4 is definitely going to look much better because it’s within the distance that it will matter. But from 3, 5, or 10 feet away the difference will be marginal, and again that’s the Point. You don’t sit even 3 feet away from a typical 40″ or 50″ TV; as the article states the average is about 9′, and in my case it’s more like 13′. Not gonna waste money on something I can’t use to it’s fullest extent.

  • Ros says:

    Great site! What formula is used to find the min distance you need to sit from the screen to enjoy the effects of 4K, i.e. not seeing jaggies? Thanks

  • [...] this debate before when HD was coming to the market and the question was between 720p and 1080p (I always refer to this article Carlton Bale), our eyes simply cannot tell the difference between 1080 and 4K at comfortable viewing [...]

  • [...] can find various mathematical solutions to this problem, but here's one that's typical and also clearly written. Its conclusion: You'd need an 84-inch screen and you'd [...]

  • [...] input your vision number). Here are a few online calculators to check out: Reference Home Theater, CarltonBale.com, and Home Theater [...]

  • [...] your vision number). Here are a few online calculators to check out: Reference Home Theater, CarltonBale.com, and Home Theater [...]

  • [...] Bale, a tech writer, has written an excellent synopsis of what 4K means for the home viewer. Looking at the offerings that Best Buy Co., Inc. (NYSE:BBY) currently has, [...]

  • Jonathan says:

    Thanks. Great information, and I appreciate it.

  • routerunner says:

    Hi, very interesting article indeed. I have one question if you don’t mind, you’re claiming that the PS3 is able to display still at 4K, but don’t you need two HDMI cables to do that?

    Eddy

  • Carlton Bale says:

    routerunner, HDMI 1.4 supports 4k (both 3840 x 2160 and 4096 x 2160) but is limited to a frame rate of 30 frames per second. This is fine for viewing movies filmed at 24 frames per second, but not for 3D content or HFR.

  • Carlton Bale says:

    It’s interesting to note that Sony lists the same recommended viewing distances in their 65X900A 4k UHD TV product description as I have calculated above (i.e. 3.6 feet for a 55″ screen and 4.2 feet for a 65″ screen.) If you don’t believe my numbers, confirmation from Sony should help convince you.

  • […] Does 4K Resolution Matter: http://carltonbale.com/does-4k-resolution-matter/  (Be sure to look at the viewing calculator at the […]

  • David Ahn says:

    Screen width would yield marginally better results for your calculator than diagonal for those with different screen ratios (mine is 2.34:1). Also, I find it odd that for my 166″ screen (16:9 equivalent dot pitch; actual diag. 158″ 2.34:1), 4K distance is 10′ but 1080p is 22′.

    I wonder if being boundary-sensing, our eyes can detect the “screen door effect” better than it distinguishes line pairs? I’ve seen a demo of a Sony 65″ 4K TV at Fry’s, and even at 5-6 feet, the lack of pixel structure is obvious compared to a 1080p set at the same distance or farther.

    • Carlton Bale says:

      David, you’re correct on both points. The chart does assume square pixels. My Home Theater Calculator spreadsheet does allow for non-square pixels and various aspect ratios.

      The black gaps between pixels are definitely a more noticeable issue, especially for brighter, mostly white background scenes. Any time there is a high contrast difference, it will be noticeable. That’s one of the reasons high contrast ratio is more important than high resolution. In general, the screen door effect isn’t nearly as noticeable as it used to be several years ago.

  • Chris says:

    Your calculations are shockingly off. In real life, for even a 46” tv at 4K resolution, the optimal viewing distance is somewhere around 11-13 feet. This is the distance where any closer you will see individual pixels, and any farther the image looks perfectly smooth. In contrast, for a 46” tv at 1080p, the optimal viewing distance is somewhere around 22-26 feet.

    The difference gets even more pronounced at larger screen sizes.

    Post the math you used to calculate the chart. Otherwise it is YOU who are selling snake oil.

    • Chris says:

      ^^ Don’t take my word for it. See with your own eyes. The image at this link is a 1080p image with no anti-aliasing. Throw the image up on your computer monitor (mine is 23 inches), then walk backwards until the image looks perfectly smooth and you can no longer see jaggies (i.e., individual pixels). Now imagine a 4K screen with the same pixel density and twice the diagonal size. Wallah. You have found the optimal viewing distance for a 46 inch 4K screen. When I do this test, I measure 13 feet. Whereas your chart suggests I should measure less than 2 feet.

      http://www.freeimagehosting.net/newuploads/rvlwr.png

      • Chris says:

        ^^ And for good measure, repeat the test with the image at the following link, which is at 540p, representing one quadrant of a 1080p image. Walk backwards until the jaggies disappear. You have found the optimal viewing distance of a 1080p screen with twice the diagonal size of your computer monitor. When I do this test with my 23 inch monitor, representing a 46 inch 1080p screen, I get an optimal viewing distance of around 25-26 feet. In contrast, your chart suggests it should be around 6 feet.

        http://www.freeimagehosting.net/newuploads/d2l8v.png

  • Carlton Bale says:

    Chris, I can assure you I’m not selling snake oil nor anything else; everything is freely available.

    As stated in the article, everything (including the calculations) is available in my Home Theater Calculator Spreadsheet: http://carltonbale.com/home-theater/home-theater-calculator/

    I do agree that most people will see the jaggies for the images you posted at distances larger than those calculated in the article. That’s because those images in no way represent real world video viewing material. It’s a pure white / pure black image, with no gray-scale / no anti-aliasing. The majority of a movie scenes are composed of gradients, and the high-contrast sharp line content that is there is anti-aliased. Astronomers will correctly point out that stars with far smaller resolutions (dots per inch) can be seen because of the high contrast with surrounding space. As in the other case, this doesn’t apply to real-world movie viewing.

    I have no incentive to post inaccurate information. The numbers Sony has posted pretty much exactly match mine, and they have a disincentive to do so. The numbers posted by THX also generally align with mine: http://carltonbale.com/home-theater/home-theater-calculator/ .

    • Fred M. says:

      You wrote: “Chris, I can assure you I’m not selling snake oil nor anything else; everything is freely available, including the calculations. As stated in the article, everything is available in my Home Theater Calculator Spreadsheet”

      That’s some rather circular reasoning; ‘you can trust what I say because I’ve produced a spreadsheet that concurs with what I say.’

      Citing Sony and THX goes a long way towards supporting your numbers, but you might want to just show a few examples in your reply just to make it crystal-clear.

      Please note that I believe that your numbers are in the ballpark (at the very least).

      • Carlton Bale says:

        Fred M.: I edited my comment to clarify. I’m making 2 points there: 1) I’m not *selling* anything and 2) that I had in fact posted the math requested by Chris via the spreadsheet linked in the article.

        The article provides the links back to the referenced Sony and THX material. I’d love to post some more examples and illustrations, but the post is already bordering on information overload as it is. :)

    • Chris says:

      Carlton – You wrote: “I do agree that most people will see the jaggies for the images you posted at distances larger than those calculated in the article.”

      By your own admission, your entire chart is bunk. Your chart is based on the premise that it reflects the maximum viewing distances at which the human eye can resolve an individual pixel based on arc-minutes. In admitting that most people will see jaggies at larger distances than those calculated in the article, you are admitting that the human eye can resolve individual pixels at distances greater than those you have calculated. Full stop.

      Your reasoning that the images I posted don’t matter because they have no anti-aliasing is a red herring. That is precisely the point. Anti-aliasing is a visual trick used to HIDE the fact that the human eye can resolve individual pixels. It makes the image blurry, or less sharp. It also requires additional processing power for digital graphics, such as video games and digitally rendered animation.

      So yes, anti-aliasing may make it so that the human eye cannot quite point out an individual pixel. That doesn’t mean that a 46” screen at 4K won’t look noticeably SHARPER than a 46” screen at 1080p, when viewing at distances of even up to 13-26 feet.

      Nice try. The images I posted are undeniable. Viewers of this site, see for yourself.

      • Chris says:

        Perhaps your premise is incorrect — i.e., that with 20/20 vision it is possible to resolve a maximum of 1/60th of a degree of an arc.

      • Fred M. says:

        Chris,

        Your understanding of human visual perception is flawed. When presented with a detail that can be seen up-close, people will still believe that they see the detail from much further away than they actually can.

        At some distance, I could replace your images with ones that were ten times the resolution (assuming such a monitor existed) and have the majority of viewers believe that they still saw the stair stepping.

        If you think that the human eye can pick out individual pixels at much greater distances, then produce a sentence with characters that are 5×7 pixels in size and then have people walk FORWARDS until they can just read the sentence.

        • Chris says:

          Fred. Did you even look at the images?

          4k quadrant:
          http://www.freeimagehosting.net/newuploads/rvlwr.png

          1080p quadrant:
          http://www.freeimagehosting.net/newuploads/d2l8v.png

          This is not some figment of the imagination. The numbers in his article are not anywhere close to reality.

          Look at the 1080p quadrant displayed full screen on a 23” monitor (representing a quadrant of a 46” 1080p image), and tell me honestly that you cannot see CLEAR jaggies at a distance of 9 feet, the quoted average viewing distance of a TV quoted in the article. This proves definitively that 4K has a clear benefit at the average viewing distance, even for screen sizes as small as 46”.

          In contrast, the calculator posted in the above article states that you would need to sit THREE FEET (3”) away from the screen to see a benefit of 4K over 1080p on a 46” screen. The images I posted prove this to be clearly, demonstrably false.

          • Carlton Bale says:

            Chris, you’re mixing together contrast ratio and resolution. You have to separate the two variables to understand the individual impact of each. If you were to look at the images you posted on a screen with a 10:1 contrast ratio, they would look smooth. As stated in the article, high contrast ratio is more important than high resolution for overall image quality.

            The issues with your images is that they do not represent real-world content. Test images represent extremes that do not reflect the way TVs in the living room are used. Let me give some examples of how relying on test images leads to conclusions that are not meaningful for real world scenarios. On one extreme is the astronomy example, with a single white pixel and a black background. If the contrast ratio is near infinite, in a completely dark room, a single bright pixel could be perceptible even on a 100 megapixel screen. At the other extreme, take a 100 megapixel test image of a pure white background. On a 100″ screen, it would look identical wither the screen resolution were 100 megapixels or 1 single pixel, indicating that resolution doesn’t matter at all. Taking these two extremes, you could argue that either 100 megapixel screen resolution is essential, or that anything more than 1 pixel of resolution is a waste. Reality, obviously, lies between these to extremes. The context needs to be in regards to watching TV shows and movies in a living room, not test images.

            You need to test resolution independently of contrast ratio. The goal of the test image should be to represent the average contrast between two adjacent pixels that comprises the types of images most often viewed in the living room. Comparing a pure white to a pure black pixel does not accomplish this, and the pure white to pure black comparison is not the basis of the resolution chart posted here. The 1/60th arc-minute standard is derived from human perception of real world images. It obviously varies person-to-person and image-to-image; in whole it accurately represents real world conditions that accurately identify where, between the two extremes, the reference point should be established.

          • Chris says:

            Carlton – You stated: “You need to test resolution independently of contrast ratio. The goal of the test image should be to represent the average contrast between two adjacent pixels that comprises the types of images most often viewed in the living room.”

            You are now backpedaling and completely changing the rules of your own stated hypothesis, which is that you calculated the chart above based on the proposition that the human eye CANNOT SEE anything smaller than 1/60th arc-minute. As you stated, “Based on the resolving ability of the human eye (with 20/20 vision it is possible to resolve 1/60th of a degree of an arc), it is possible to estimate when 4k resolution will become apparent for the average eyeball.” You did not differentiate contrast ratio. Nor should you. This is because the goal of a higher resolution screen is to get the sharpest image possible, meaning that the human eye cannot see an individual pixel at ANY contrast ratio, thus eliminating the need to blur the image with anti-aliasing.

            You did not address my proposition that, at normal viewing distances of 9 feet, a 4K image on a 46” screen is likely to look SHARPER to the human eye than a 1080p image, even if anti-aliasing blurs the 1080p image to hide the aliasing.

            Nor did you address the very real-world application of video games and computer generated animation, all of which suffer from aliasing.

            In the end, you spout a lot of talk. But I have produced a verifiable experiment (the images posted above) that directly refutures your claims (e.g., that you need to be within 3 feet of a 46” screen to observe the difference between 4K and 1080p). In contrast, you have produced no proof whatsoever to support your calculations, other than repeating the mantra that your 1/60th arc-minute premise is an accurate measurement of human visual acuity.

          • Fred M. says:

            Chris, yes, I looked at the images. I’ll look at them again if I’m ever in the market for a monitor on which to view black and white, single-bit-per-pixel still images.

            But such images are meaningless as a test for the benefits of a 4K color television. The human brain processes color, contrast, and motion in a more complex way than is represented by B&W still images. That’s all part of how we perceive detail.

            Look at this image, which is a cat’s face produced by mirroring the right side to the left.

            http://www.anti-spam.org/cat_face.bmp

            The left half is 960 x 540 resolution and the right half is 1920 x 1080. No interpolation tricks were employed — simply cut the resolution in half and then double it via pixel doubling (1 pixel becomes 2×2 pixels). The stair-stepping which you claimed to be so visible at 9 feet on a 23″ monitor isn’t really visible, is it?

            Adding motion further discredits the notion of black and white still images as a test; the brain’s processing of motion completely masks any difference in screen resolution.

            The only valid test of 4K vs. 2K is an ABX test conducted with actual program material (movies, for example). Show me that there is a statistically significant ability by the test subject group to pick out the 4K rendition at that distance and then you’ve got something.

          • Carlton Bale says:

            That’s a great picture Fred. Thanks for posting it. I hadn’t seen that before.

          • Fred M. says:

            You hadn’t seen the picture before because I just created it for this discussion. You’re free to use it as you see fit. Thank you for the web site and this discussion.

          • Fred M. says:

            As an aside, you need to lose the nasty tone in your replies to Carlton Bale. He’s not “backpedaling” or “changing the rules.” He didn’t ‘admit’ that his “entire chart is bunk.” That kind of juvenile tone is making you sound like some angry kid who thinks that he’s smarter than all of the adults.

            Carlton Bale has provided, at no charge to visitors, a website and series of tools that many find to be useful and informative. But since you doubt Mr. Bale’s knowledge, methodology, and integrity, let’s look elsewhere:

            cnet.com article: “Why 4K TVs are stupid
            There’s all this buzz about 4K resolution. You don’t need it, and probably never will.” included: “The human eye, for all its amazingness, has a finite resolution. This is why you can read your computer screen from where you’re sitting, but not if you’re on the other side of the room. Everyone is different, but the average person with 20/20 vision can resolve 1 arcminute. One arcminute is 1/60th a degree. If you assume your field of vision is 180 degrees (it’s not, but go with me here), and you take 1 degree of that, you’re able to resolve a 1/60th sliver of that degree.”

            Gee, that matched the numbers Carlton Bale used, didn’t it? The article goes on:

            Joel Silver, founder of the Imaging Science Foundation, which consults with the TV industry on manufacturing displays, said that the most important specification is not resolution; it’s dynamic range. The darkness of the blacks is what’s most important. The next most important specification he named was color saturation; are the reds really red? More specifically, are they as red as they should be and not too red, either.

            Next on his list was color accuracy. Do skin tones look as they should?

            Mr Silver said “The last thing we look at is resolution.”

            If you’re going to argue that Carlton Bale, editors at cnet, writers at the New York Times, and consultants to the TV industry are all wrong, you better have something better than some static, black and white images.

          • Chris says:

            Fred – Your cat image is merely an example of how anti-aliasing blurs an image to hide the fact that the human eye can resolve individual pixels. All natural images have anti-aliasing as a result of sampling of an infinitely sampled image (reality). This doesn’t mean that a higher resolution image won’t look SHARPER, even if you cannot quite make out individual pixels in either image because of anti-aliasing.

            Additionally, your image does not address the real-world application of video games and digitally rendered animation, all of which suffer from aliasing unless you employ processor heavy anti-aliasing algorithms, which blur the image and make it less sharp. Aliasing is made even more noticeable by motion, because it introduces flicker and shimmer to edges.

            And again, you have provided no support for the article’s premise that the chart reflects the maximum distances from which the human eye can resolve individual pixels. You have again merely quoted the 1/60th degree standard as gospel, despite the fact that my test image proves it to be incorrect. If it were correct, you would not need anti-aliasing to hide stair stepping at the distances cited in the chart.

          • Fred M. says:

            Chris, as I stated before, each “pixel” on the left is four physical pixels (2×2). Pull it up in a graphics editor and do some pixel peeping if you doubt me. Then step back 9 feet from that and tell me if you see a difference.

            “This doesn’t mean that a higher resolution image won’t look SHARPER, even if you cannot quite make out individual pixels in either image because of anti-aliasing.”

            Then step back 9 feet and tell me if one side looks sharper than the other.

            “Additionally, your image does not address the real-world application of video games and digitally rendered animation,”

            And your black and white, still-frame test pattern does? If you’re going to claim that you can see the difference between a 2K and a 4K monitor at 9 feet with a video game, then prove it, using a video game, rather than making unproven assertions that fly in the face of years of medical research.

            “You have again merely quoted the 1/60th degree standard as gospel, ”

            Sixty pixels per degree corresponds to recognizing the letter “E” on the 20/20 line of a Snellen eye chart at the prescribed distance of 20 feet. The Snellen Fraction of 20/20 represents standard visual acuity and corresponds to 60 pixels per degree and 30 line pairs per degree. Therefore, it is gospel. If you’re going to claim that the medical community is wrong, you better have something more convincing than your black and white image

            “despite the fact that my test image proves it to be incorrect.”

            No, your image is a test of “vernier acuity,” the ability of the people to pick out misalignment of high-contrast pixels. Humans are an order of magnitude more sensitive to pixel misalignment (vernier acuity).

          • David Ahn says:

            Chris… chill out, dude! I do partially agree with you; with your black & white, jagged, still image, I can see some minimal jaggies at 11+ ft from my 15.6″ retina MBP screen (image 14.1 x 7.9″, 16.2″ diag, equiv. to a 32.4″ 4K screen). But that image is VERY unlike anything I’ll be watching in my theater. The cat image is much more real-world, and at 24″ from my monitor, it is hard to tell the difference between 540p and 1080p except in the fine hairs (the photo could be sharper). Add in motion, and our ability to appreciate the extra resolution decreases dramatically.

            Bottom line, I prefer to sit closer than the 36 degrees viewing angle/1.5 times picture width THX recommends, and with my 20/15 vision, I fully expect to see more clarity and a lot less pixel structure (8′ from the 158″ 2.34:1 screen). Will my theater guests notice the difference? Probably not, especially from the back of the theater (18′ from the screen), but I will certainly relish it from my front row seat.

            PS, Carlton, please post a higher resolution background image of your theater room… what a jagged eyesore on my retina MBP at 24″ from the screen! LOL (Joking about it being an eyesore, not about the visible jaggies. :)

          • Chris says:

            Fred – Per your request for a blind side-by-side test:

            “Earlier this month, we set out to investigate if the extra resolution offered by 4K over 1080p is visible at normal viewing distance, as part of an Ultra HD and OLED television showcase event organised by British retailer Richer Sounds. A 55-inch 4K UHD (ultra high-definition) TV was lined up alongside a 1080p HDTV of the same size, each displaying content that’s 1:1 pixel-matched to its native screen resolution. Both TVs had their identities masked by custom-built cabinets which were spray-painted black. Standing 9 feet away (enforced using crowd control posts), attendees were then asked to pick out the 4K television after sampling the displayed material.

            The results are now in, and an overwhelming majority of participants correctly identified the 4K TV, indicating that there exists a perceptible difference even from as far as 9 feet away on a 55in screen. Out of 49 attendees who submitted their pick to enter a prize draw, only one thought that the 1080p set was the 4K display.”

            - Vincent Teoh, 4K Resolution Is Visible vs. 1080p on 55” TV from 9′ Viewing Distance, HDTVtest.co.uk (Dec. 15, 2013).

          • Fred M. says:

            Chris,

            Thanks for pointing me to that test. I did read the article and found it unfortunate that they used two different televisions models with different panels. I’d have preferred two identical 4K televisions, with one receiving 2K and the other receiving 4K content. That way, the panel differences that they noted in their article would not have been present.

            I’d also be very interested to see whether your contention that a 46″ at nine feet would have been properly identified, since the 55″ screen is 20% larger than a 46″ screen.

            The article also went on to say that “resolution is only one of the many attributes of picture quality, and not the most important one. Amongst the swarm of 4K televisions on exhibit, it was actually a full HD 1080p set – the LG 55EA980W OLED TV – that hogged the attention of those attending the event, largely due to its ability to render true 0 cd/m2 blacks, contributing to an unrivalled contrast performance (which most video enthusiasts agree is the principal determinant of image quality).”

          • David Ahn says:

            Identical 4K panels displaying 4K vs. 2K material would have tested viewers’ ability to distinguish the resolution, but not the impact of the screen door effect. For me, greatly reduced visible pixel structure is a large part of what excites me about 4K.

            I disagree that contrast is more important than resolution or lack of pixel structure, since digital home theater projectors exceeded the blacks of movie theaters (at least film projectors) years ago, yet people still love the huge screen experience of a theater. I am quite anxious to see 4K vs 2K PJ material in person to judge whether 4K PJs are worth 4X the price for my home theater.

          • Chris says:

            Fred – I do not dispute that other aspects to image quality matter as much if not more than resolution. That is not the dispute here. The dispute is whether the human eye can visually see the added resolution. All real world test evidence points to yes.

            I’m sure the 1080p OLED screen does look better overall, due to the higher contrast ratio, response time, and color depth. However, I’m also sure that a 4K OLED screen would look even better still.

  • […] a tabela abaixo, de Carlton Bale, convertendo a distância de pés para metros. Ela bate com as recomendações da Sony e da THX e […]

  • Boris says:

    too many comments to read here, but i thought i would make you aware of an oversight in this post. i wont comment on the topic as i agree with some but not all, but one thing i want to say is the resolution calculator is set to state x amount of feet or CLOSER for full benefit. This should be x amount of feet away or FURTHER for full benefit.
    I am sure i dont have to explain how sitting closer exposes more pixelation. So ideally, you should sit further away to avoid seeing pixelation. Recommend correcting this so as not to confuse or mislead people. The rest of your post is an opinion but this component is shown as factual and can be if corrected.

    • Carlton Bale says:

      Boris, I get this feedback frequently and can see the reason for confusion. The page is correct in that you must sit at the specified distance or closer to get the full benefit, and let me explain why. You have to be at least close enough to a TV to experience the full resolution. For example, if you were 50 meters away from a 4K screen, it would look exactly like a 1080p screen and a 480p screen. As you get closer (much closer), you can start to tell the difference between the resolutions. Once you reach the distance calculated, you will be able to see the full resolution of the screen. Getting closer will yield no additional resolution benefit, but there is also no negative impact. But as you stated, as you get significantly closer, the pixel structure starts to break down and you can see individual pixels. This happens at a distance closer than the minimum distance calculated above.

      The breakdown in pixel structure is highly dependent on display technology and is largely related to the fill ratio of each individual sub-pixel. On an ideal display, the fill ratio would be 100% and you wouldn’t be able to discern pixels even if your eye were about to touch the screen. Because fill ratio varies so much between displays and display technologies, it’s impossible to estimate a universal distance at which this happens. But for all modern displays, fill ratio is high enough that happens at a distance closer than the “full benefit distance” calculated above.

  • Bill says:

    The one thing missing from this is the advantages in aliasing you get with higher resolutions as well as the elimination of the screen door effect. There have been studies that indicate the brain still picks up the “static”from the spaces in between pixels and smooths it out via its own interpretation.This is why when viewing the checkerboard pixel by pixel test, you can sometimes see purples or greens. As it is creating a moire effect.

  • […] it look smoother and crisper. If you want some super-technical, brainhurty info on the subject, check out this article by Carlton Bayle which even includes a 4K a spreadsheet calculator to get optimum […]

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