4K and HDR

“4K” is the new higher-resolution standard for Blu-ray titles. HDR stands for another new technology called high dynamic range. HDR is a much more important advance than 4K. These two new technologies are not linked to each other. So let’s look a bit closer at each of them. Sorry, we don’t have any way now to make proper screenshots showing the benefits of 4K or HDR.

4K

"4K" is my lazy way to say "4K Ultra HD Blu-ray", the latest video format. "2K" is what I call the old Blu-ray format, which came out in 2008. 1K is what I call a DVD. See the table below explaining this. First, the table shows where I get the 1K, 2K, and 4K terminology from: the 720 vertical lines on DVD rounds to 1K, 1920 on Blu-ray rounds to 2K, and 3840 on Ultra HD rounds to 4K.

Format Resolution Pixels Color Gamut HDR
1K DVD 720 × 480 345,600 16.8 million (8-bit) No
2K Blu-ray 1920 x 1080 2,073,000 16.8 million (8-bit) No
4K Ultra HD 3840 × 2160 8,294,400 1.07 billion (10 bit) Yes

Now let’s compare 1K DVD to 2K Blu-ray. There is a belief I've heard about many times that you can't get a consumer to move to a new product format unless the new deal is something like 10X better than the old. Just call it the "way better" rule. LPs were way better than 78s, CDs were way better than LPs, and DVDs were way than better than VHS movies, etc. Now the table shows that 2K Blu-ray has about 6X more pixel density than 1K DVD. It's not too hard to show that 2K Blu-ray is "better" than 1K DVD. But 2K flunked the way-better rule. Some folks had trouble seeing the difference. Others easily could see the difference, but didn't think the improvement was worth fussing over.

Now let’s consider 4K to the older form factors. 4K has 4X the pixel density of 2K Blu-ray. But compared to 1K DVD, 4K Ultra HD has 24X the pixel density (345,600 x 24 = 8,172,000). Hey! When comparing DVD to 4K, we are talking "way better." And in addition to resolution, 4K bests DVD with better color and better sound reproduction. So I did some pseudo-scientific tests to see if 4K really has a chance to finally kill off DVD.

There are a  handful of fine-arts video titles in 4K out now. I have played them all on new 4K gear (which can still play my old 2K and 1K titles as well). So the first test was a direct comparison between a DVD version of a Le Nozze di Figaro and the 4K version of the same title. Yes, 4K is indeed superior to DVD. The detail, clarity, and color vibrancy are all vastly improved with 4K. In blind A/B comparisons of the same scene, (the 4K running on my 4K-capable Oppo and the DVD running on my region-free Sharp player) provided no challenge. I was able repeatedly to correctly identify each disc instantaneously.

Granted—comparing the DVD and 4K pictures to each other simultaneously is an easier test than just walking into a room and making a call upon seeing a single image. But the difference revealed by my A/B test was stark, dramatic, and convincing—I think people will easily see the difference in DVD and 4K images.

My last step was to compare a new 2K Blu-ray title to a 4K version of the same title. My test case was the new disc of the Benoît Jacquot Tosca, which was filmed on 30-mm film in the 80s. It comes in a box with a 2K and a 4K version (without HDR). Here I had trouble getting excited about the 4K as contrasted with the 2K disc.

Conclusion: nobody will have any trouble seeing that 4K Blu-ray is way better than 1K DVD. But the difference between 2K and 4K (without HDR) is not so dramatic.

4K is an important step forward. But wait, I said that HDR is even more important than 4K.

HDR

With HDR, special lighting values are baked into the disc and displayed by the new HDR TVs. This allows for a much greater difference in luminescence across the various areas of the screen than was ever possible before. To test the effect of both 4K and HDR used together, I first bought two science fiction films: The Cabin in the Woods and Arrival. These titles have two discs each: 1) a 2K Blu-ray and 2) a disc with both 4K and HDR. Now suddenly the advantage that 4K + HDR has over 2K Blu-ray is easy to see. The (1) better resolution, (2) enhanced color gamut of 4K, and (3) greater brilliance of the HDR images work together to leave 2K Blu-ray in the dust.

Finally, in early 2019, I had a chance to compare a 2K Blu-ray version of Khatia Buniatishvili playing piano concertos with a 4K/HDR version of the same performance. The 2K Blu-ray version looked dark and drab. But the 4K/HDR version seemed to be the most brilliant video of a classical movie concert that I had ever seen. On repeated viewing of the 4K/HDR I could see that the color balance in the video was off and that the whole picture looked unnatural, but it was bright for sure.

Well, it’s now been more than 3 years later in March 2022. I keep seeing all kinds of fantastic high resolution clips on YouTube with HDR. Several hundreds of action films have been published in native 4K with HDR. But not even one additional classical fine-art Blu-ray with HDR has been released by an established publishing house. The tech is there and available, but it appears nobody thinks you can make a profit on it with a fine-arts subject.

Conclusion: 4K + HDR ought to render obsolete both 1K DVD and 2K Blu-ray in the fine-arts space. But we will not know about this until somebody has had the guts to give it a try.

March 26, 2022