Christie HDR Demo at NAB 2016

Other than the high frame-rate clip from Ang Lee’s upcoming movie Billy Lynn’s Long Halftime Walk, one of the most impressive demos I saw at NAB 2016 was presented by Christie Digital. In collaboration with Dolby, the company co-developed the high dynamic-range (HDR) projectors found in Dolby Cinemas, but in this case, the HDR was pure Christie, not Dolby Vision.

The projector was a 4K, 3-chip DLP engineering prototype utilizing RGB lasers as the illumination source. Firing onto a 16-foot-wide, matte-white Da-Lite screen (0.9 gain), it produced a peak luminance of 200 nits (56 foot-lamberts)—four times the brightness of a conventional digital cinema and nearly twice as bright as a Dolby Cinema—and a color gamut that reached all the way to BT.2020. And like a Dolby Cinema projector, this one had a claimed contrast ratio of over 1,000,000:1.

The demo included several parts played at 24 fps, starting with a demonstration of standard and high dynamic range with full-screen black fields. When the projector switched to HDR, the audience literally gasped as how the screen completely disappeared. Fortunately, the small demo space—dubbed the Innovation Theater—was completely blacked out with no exit signs or other lighting.

Then, we saw some CG renderings of an automobile engine and slow-moving footage of parked cars that switched between SDR and HDR while the recorded voiceover pointed out how much more shadow detail was visible as how much brighter the specular highlights were. Interestingly, this footage was not mastered in HDR; instead, Christie processing expanded the dynamic range in real time, and it looked excellent.

Next up was a clip from Dark Universe, an educational short narrated by astrophysicist Neil deGrasse Tyson. Again, this selection was not mastered in HDR, but it looked spectacular anyway. (BTW, if you get a chance to see it at the American Museum of Natural History or the Hayden Planetarium in New York City or the Smithsonian in Washington, DC, by all means do. It’s an excellent exposition of modern cosmology.)

Finally, we saw the trailer for Mad Max: Fury Road, which had been mastered for HDR and BT.2020 color especially for this demo. As expected, it looked fantastic, with deep blacks, amazing shadow detail, vivid colors, and startling brightness where needed.

When I expressed my concern about expanding the dynamic range of SDR content to Mike Perkins, principal product developer at Christie, he said that increasing the brightness of good SDR images is often not a problem. However, he also said that pushing it above about 400 nits can look pretty bad, especially with people in the image, since humans are so sensitive to how other humans look. But the SDR footage in the demo had no people in it, and it was pushed to “only” 200 nits, so he was confident that it would look fine—and it sure did!