The work to define an HDR cinema specification that began earlier this year has now become a “version 0.9” draft that also details HFR (High Frame Rate) requirements.
High Dynamic Range cinema
Cinema has historically been at the forefront of video and sound innovation. However, in the transition to HDR – video with expanded luminance and color range – consumer TVs have taken the lead.
DCI (Digital Cinema Initiative), created in March 2002 as a joint venture between 20th Century Fox, Disney, Paramount, Sony Pictures, Universal and Warner Bros., has spent months working on HDR cinema specifications. The work began in earnest this summer with a proposal. DCI has now publicly released a “version 0.9” draft “for review and comment prior to publication of a final requirements document by DCI”.
- “The future of HDR Cinema is near! After many months of intense work, I’m proud to see the release of the DCI DRAFT HDR & Direct View Display specs,“ said Michael Zink, VP Technology, Warner Bros. and Chairman, UHD Alliance.
The two draft documents are highly technical, complete with specifications and formulas, but can essentially be boiled down to this: DCI wants to use PQ (Perceptual Quantizer), 12-bit video for HDR, a minimum black level of 0.005 nits, and 500 nits peak brightness. It is based on the P3D65 white point and a color space that corresponds to DCI-P3, which consumer HDR TVs also use.
Direct view displays
One of the big changes is an HDR cinema draft specification for “direct view displays”, essentially huge LED displays built from modules. Theaters will still be allowed to use projectors but the numbers specified in the ‘High Dynamic Range D-Cinema’ draft will be hard to achieve, unless new projection technology is developed.
This could lead to a fundamental change in an industry that has used projection technology for over hundred years.
- “D-Cinema Direct View Displays provide the potential for an improved high-quality image through significantly increased peak luminance and dynamic range, but may also be used to present legacy content” the draft said. “Since these displays use emissive technology (often LED pixels) rather than a projected image, the image quality can be excellent, even in viewing environments with moderate ambient light.”
Another change is HFR or High Frame Rate – much smoother video. Specifically, DCI is detailing “edit units per second” requirements for direct view displays as well as reference displays used in studios, essentially laying the foundation for HFR cinema – at least in 2K resolution. Today, all Hollywood movies with very few exceptions are shot and reproduced in 24 frames per second.
The draft details up to 120 frames per second for 2K 2D. It also requires direct view displays and reference monitors to support a minimum of 60 frames per second for 2K 2D and 24 frames per second for 4K 2D. These are required levels and direct view displays can go further but this is beyond the specifications proposed in the draft.
If the HDR cinema specification ends up being based on definitions in the version 0.9 draft, cinemagoers can look forward to much more contrast-rich, color-accurate, and sharper images that better match what viewers are experiencing at home with the latest HDR TVs – but on a much bigger screen. On the other hand HDR will require exhibitors to make significant investments in new equipment.