UHD Alliance Sets HDR Requirements

[Jon Fairhurst]

..."For devices, the UHD Alliance said a 'Premium' logo can only be borne by a screen that displays an image resolution of at least 3840 by 2160 pixels, with a display reproduction capable of 90 percent of P3 colours and a 10-bit signal for colour depth.

"HDR requires one of two standards -- reflecting the intrinsic differences between OLED and LED screens -- capable of more than 1,000 'nits' peak brightness at less than 0.05 nits black level (LED), or 540 nits brightness with 0.0005 black level (OLED)."

'UHD Alliance' finally decides what 'next-gen' video actually is (Wired UK)

[Jon Fairhurst]

Here's the full press release:

UHD Alliance Defines Premium Home Entertainment Experience | Business Wire

For those interested in distribution and mastering requirements, here are the highlights:

Distribution

Any distribution channel delivering the UHD Alliance content must support

Image Resolution: 3840x2160
Color Bit Depth: Minimum 10-bit signal
Color: BT.2020 color representation
High Dynamic Range: SMPTE ST2084 EOTF


Content Master

The UHD Alliance Content Master must meet the following requirements:

Image Resolution: 3840x2160
Color Bit Depth: Minimum 10-bit signal
Color: BT.2020 color representation
High Dynamic Range: SMPTE ST2084 EOTF

The UHD Alliance recommends the following mastering display specifications:

Display Reproduction: Minimum 100% of P3 colors
Peak Brightness: More than 1000 nits
Black Level: Less than 0.03 nits

[Tom Roper]

Are you shooting, grading HDR Jon?

[Jon Fairhurst]

I'm not doing HDR just yet, but I'd love to. We'll all be going that route eventually - and we'll love it. :)

The main thing holding me (and us) back is the monitor. I could shoot photos on my 2008 5D2 and make a slideshow, or I could use Magic Lantern and shoot raw video. Or I could buy/rent any number of cameras that capture 12 bits of dynamic range or better. The capture side is easy.

In fact, it will become easier as we won't have to light things as flat as before. I attended a SMPTE presentation by Howard Lukk on his shooting of Emma in HDR last year. He found that he needed fewer lights and scrims than normal, though one still has to ensure enough light on faces vs. source lights in order to draw the attention to the talent.

In post, I can already use the ACES feature in Vegas and many other NLEs. Sony's Catalyst series is being developed from the ground up around an HDR-capable workflow.

But then there's the monitor. HDR reference monitors are priced in the tens of thousands of dollars range. I've heard that the Dolby Vision monitors are "lease only" and much of the finishing work is done at Dolby Labs. That situation holds you and me back, but not the studios. The studios are quite bullish on HDR.

The new 4K UltraHD Blu-ray format supports HDR (including the UHD Alliance Premium requirements) and will include both SDR and HDR grades on a single disc. Yes, one can tone map HDR down to SDR, but that's not always ideal. I spoke with a colorist at Dolby who said that initially, they maintained mid-gray and just let the highlights sparkle in HDR. Over time, they learned that HDR gave more artistic freedom. For instance in SDR, one might grade a couple at a fireplace simply for the overall look and technically to cram the flames into range while battling to not lose too much detail. With that same scene, HDR allows the colorist the freedom to grade the faces to look hot from the flames or dim and distant without risking blowing out the whites - all while using less light on set.

Anyway, Amazon now streams a number of titles in HDR. Netflix and others are hot on their tails. Hollywood is grading virtually all of their high budget stuff for HDR masters and will release HDR titles as soon as 4K Ultra HD discs gain steam.

To quote a recently popular line, "It's true. All of it."

But we need HDR monitors to become available and affordable before us indies can join in the fun. (And we need video card drivers to support SMPTE ST2084.) Then again, a new HDR Alliance Premium TV could make a nice monitor, couldn't it?

Frankly, I'm surprised that more people here aren't excited by it. But maybe they haven't seen it in person. To my eyes, it looks fantastic.

[Chip Gallo]

Stacey Spears of Spears & Munsil said this on another forum recently:

"For me, personally, HDR is where it is at. I think HDR is the biggest advancement since HD. Maybe since color television. We have been limited to 8-bit 100 nits for so long."

[Jack Zhang]

Standards are great... a unified SMPTE 6G and 12G SDI standard is still but a pipe dream cause no work has been done on this and we've been stuck with 4x 3G-SDI links.

NO, Blackmagic's standard is proprietary and rides on top of 3G-SDI standards.

It's 2016, people. HDMI has well surpassed SDI on this front and SMPTE hasn't even moved an inch on 6G and 12G SDI standards.

[Tom Roper]

Originally Posted by Jon Fairhurst

I'm not doing HDR just yet, but I'd love to. We'll all be going that route eventually - and we'll love it. :)

The main thing holding me (and us) back is the monitor. I could shoot photos on my 2008 5D2 and make a slideshow, or I could use Magic Lantern and shoot raw video. Or I could buy/rent any number of cameras that capture 12 bits of dynamic range or better. The capture side is easy.

In post, I can already use the ACES feature in Vegas and many other NLEs. Sony's Catalyst series is being developed from the ground up around an HDR-capable workflow.

But then there's the monitor. HDR reference monitors are priced in the tens of thousands of dollars range. I've heard that the Dolby Vision monitors are "lease only" and much of the finishing work is done at Dolby Labs. That situation holds you and me back, but not the studios. The studios are quite bullish on HDR.

The new 4K UltraHD Blu-ray format supports HDR (including the UHD Alliance Premium requirements) and will include both SDR and HDR grades on a single disc. Yes, one can tone map HDR down to SDR, but that's not always ideal. I spoke with a colorist at Dolby who said that initially, they maintained mid-gray and just let the highlights sparkle in HDR. Over time, they learned that HDR gave more artistic freedom. For instance in SDR, one might grade a couple at a fireplace simply for the overall look and technically to cram the flames into range while battling to not lose too much detail. With that same scene, HDR allows the colorist the freedom to grade the faces to look hot from the flames or dim and distant without risking blowing out the whites - all while using less light on set.

Anyway, Amazon now streams a number of titles in HDR. Netflix and others are hot on their tails. Hollywood is grading virtually all of their high budget stuff for HDR masters and will release HDR titles as soon as 4K Ultra HD discs gain steam.

To quote a recently popular line, "It's true. All of it."

But we need HDR monitors to become available and affordable before us indies can join in the fun. (And we need video card drivers to support SMPTE ST2084.) Then again, a new HDR Alliance Premium TV could make a nice monitor, couldn't it?

Frankly, I'm surprised that more people here aren't excited by it. But maybe they haven't seen it in person. To my eyes, it looks fantastic.

I've been involved with it, have commercial work re grading content to HDR shot with Red Epic and also 5D2 16 bit tiff images, as well my own demo reel shot with my personal PMW-F55. SMPTE 2084 EOTF is a real stress test on codecs, so the "artistic freedom" it gives demands the very best from workflows, raw, log, uncompressed. At this point for me, it's simple and easy but I've been at it, have the workflows, methods and processes worked out to do it quickly. But first hand I only know about a half dozen others doing it, and about a dozen more I assume are doing it. Ben Waggoner or his staff do the HDR re grades for Amazon. I was contacted by a guy from SpectraCal, some of them were going to get into it with the Red Weapon, maybe even Stacey Spears. But then there is the studio involvement and the patent holders, Sony, Universal, Disney, Warner Brothers, Fox, folks there operate under NDA. Broadly speaking, HDR is the hot topic among home theater enthusiasts and owners of HDR compliant UHD displays from Sony, Samsung, LG, Panasonic, Visio to name a few. Almost none of the independent film makers, the ones who have the largest body of content to contribute are remotely knowledgeable or even interested, although a few are (you). Some are writing about it like some wave of the future, but the reality is it's been here for months and most are missing the boat for this exciting development from Dolby, or few care.

Here is a download link (google drive) to my HDR demo reel. It's 3 minutes long, shot with the PMW-F55 in S-Log3, graded in DaVinci Resolve using ACES, rendered uncompressed with P3 color space and SMPTE 2084 EOTF (PQ perceptual quantizer), 1000 nits target. It is delivered in 10 bit HEVC with st-2086 meta data, mastering display volume. The latter is what switches HDR mode "on" in the latest generation of UHD displays supporting HDR. You can play the file on any set that will play 10 bit HEVC, but if it doesn't support HDR, it will look like the flat log graded image that it is, and not have the "pop." If it is played on a HDR compliant display, it will likely seem stunning because unlike 709 gamma where 5-6 stops are compressed into the range of 90-109% and represented by an actual 2-3 stops, with HDR 5-6 stops of highlight range are displayed as actual doublings of the brightness as in real life. That is the fundamental difference, PQ gamma is the transfer of sensor voltage to actual scene brightness whereas conventional 709 gamma relates sensor voltage to a gamma curve based on the display characteristic of a 1932 CRT.

https://drive.google.com/file/d/0B7w...ew?usp=sharing