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Comment by beloch | Hacker News Reader

For a small to medium displays at typical viewing distances (this includes most "big screen" panels you can buy at your local electronics shop), 1080p meets or exceeds the limits of the typical human eye's resolving power. Without using a projection system and a large screen or a stupendously expensive (>100" diagonal) flat-panel, 4K is a subtle upgrade at best.

When video is encoded with insufficient bandwidth, compression artifacts (e.g. macroblocking) are anything but subtle. These artifacts typically are not constrained to one or two pixels, but ramify to much larger portions of the image. Netflix has, by necessity, used insufficient bandwidth on practically their entire library. My money is on Netflix's over-compressed 4K being inferior in quality to Bluray 1080p for the vast majority of users.

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This might be useful in illustrating your point: http://s3.carltonbale.com/resolution_chart.html

Am I the only one who watches stuff on his computer, and sits about 2-3 feet from it?

What screen size are you on? 27 inches? Can you make out individual pixels with film material (which usually has no sharp edges in it)?

Not arguing against what you are saying, but there's a significant difference between "making out individual pixels" and "noticing a difference".

That's true.

I watch most things on my 13" mbp w/retina. and my eyes are typically 1-2 feet away from the screen. Very immersive experience IMHO.

This illustrates the point of dimishing returns with regards to ever higher amount of total pixels on a screen.

Doesn't mentions compression artifacts, though. Thus - at the same bitrate - higher resolution images might look worse than lower resolution ones. Which is what I think the OP meant to highlight.

> Thus - at the same bitrate - higher resolution images might look worse than lower resolution ones.

But the 4K stream is HEVC (H.265) vs H.264 for the other HD streams, so it may not be that simple.

Well, HEVC compresses the same quality to about half the size of H.264, so since 4K is about 4x 1080p and the bitrate is a little over 2x their 1080p Super HD streams I'd expect the quality to be a little better.

What I'd really be interested to see is the House of Cards intro at this bitrate - the 1080p Super HD stream had a lot of really off-putting banding in the clouds.

> HEVC compresses the same quality to about half the size of H.264

Eh, it's supposed to, but it's not there yet. The best H.264 encoder (x264) is actually still more efficient than the best H.265 encoders (and MUCH faster).

Development of the H265 encoders is progressing fast though, x265 will likely surpass x264 within the year.

Here's some recent samples (12th June) that compares a very recent build of x265 with x264: http://forum.doom9.org/showpost.php?p=1683608&postcount=907

Alternatively, http://isthisretina.com offers a simple way to input whatever value you need. Not that the computation is complex, but it's quite handy.

That imperial system.

That's total BS, you can notice alising patterns easily at much higher resolutions than your suggesting.

http://en.wikipedia.org/wiki/Aliasing

PS: I noticed issues standing ~10 feet from a 50' 4k screen.

I see various claims about the uselessness of 4K all over the web usually combined with words like "visual acuity" and "resolve". So, yeah, it might not be a huge deal in many cases, but saying that you need a 100"+ screen to tell the difference is just wrong. In this test, viewers easily tell the difference from 9 feet on a 55" screen:

http://www.hdtvtest.co.uk/news/4k-resolution-201312153517.ht...

This is not a weird audiophile kind of thing, these are very noticeable differences.

All that said, I'm more excited about all of the other improvements coming to display technology these days: HDR, wide gamut, high/variable FPS, low persistence, etc.

Requiring a 55" screen to tell the difference is still outside the realm of the VAST majority of home setups. I don't even know anyone with a screen that large other than a single friend of a friend with an expensive home theater room with a full-screen projection setup. And it doesn't do 4K.

For my anecdote I will state that I know quite a few people with screens larger than 50 inches. None with 4k since it is so cost prohibitive, but that can change when the cost of 4k screens comes down.

The test is still relevant: most people (especially those with smaller TV's) sit closer than 9ft away, in my experience.

All of my nearby friends do. But then, I live in NYC. So, the biggest TV of a nearby friend is 45". Then again, most folks I know in CT and CA stick to around 42" even in much larger houses.

There are advantages other than just the high resolution available under the UHD/4k umbrella (ITU-R BT.2020). The BT.2020 colorspace provides a wider color gamut, increased bit depths reduce color banding, supports 4:4:4 chroma sampling and up to 120Hz progressive frames are standardized.

Of course that doesn't mean Netflix can or will make use of any of them in their releases.

Put another way: Due to the low bitrates used by Netflix, the 4K streams will show a dramatic improvement in quality even on 1080p screens.

That's for a display that you sit several metres away from in a living room. For a closer seating (2-3m) with a 50" panel it is noticeable though (I've tried).

For a ~30 inch computer display at desktop viewing distance, the difference between 2560x1440 (which is larger than HD already!) and 4K is clear to see.

Exactly, it would be nice if I could watch 4k content on my MacBook Pro, while not full 4k, it's close enough where I would be able to tell the difference.

Strange how it's only TVs currently.

Wasn't the color spectrum increased with the 4k standard too? Would this be noticeable?

More colours in the compression artefacts? /s

I wonder what will be the gold standard for something like oculus rift?

I'm guessing the same as for print (600-1200dpi). The oculus rift guys seem to think, even a little higher:

"“If we want the “perfect” Oculus Rift, with 180 degrees FOV and an APD of 45, we’ll need a screen with a resolution of 8000 x 4500″ This matches up very well with Luckey’s comment of 8K per eye. Using a PPI calculator, a 7″ screen with resolution of 8000 x 4500 would require 1311 PPI."

http://www.gamasutra.com/blogs/IvanBlaustein/20131029/203543...

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