The introduction of HDR displays (HDR) is as big an advance, for the filmmaking and television industry, as the switch from black and white to colour.
The human eye is an incredible organ – in normal circumstances it has the ability to capture 10 – 14 stops of latitude (from dark to light), but because we have two of them and the eye reacts so quickly, our dynamic range in a single panorama can be as high as 20 – 24 stops.
This wide dynamic range is the reason why nothing can match the visual splendour of an early morning sunrise or moody sunset. Cameras have, for a long time, been able to capture these kinds of dynamic range, the problem is that it hasn’t been possible to display the true captured results – until now that is, thanks to the implementation of HDR (high dynamic range) displays.
Three years ago, 4K resolution video was being touted as the next big advancement in picture quality. All the major TV set manufacturers released new lines of 4K sets and in the following months, Over-The-Top (OTT) services like Netflix began offering 4K titles, sports networks began capturing and producing events in 4K, and pioneering pay-TV service providers began offering 4K selections in their Video-On-Demand (VOD) catalogues.
But 4K resolution is just one piece of a larger, more complex, next generation video standard called Ultra High Definition (UHD). The UHD Alliance is an industry body comprised of software developers, hardware manufacturers, content producers and pay-TV providers, that have defined a set of parameters for UHD that include but ultimately go beyond 4K resolution. Those parameters include high frame rate, wider colour gamut, deeper colour depth, and high dynamic range (HDR). In fact, HDR is the new, next major advancement in picture quality. While the TV set makers jumped in on offering higher resolution sets, content creators are now embracing the benefits of HDR as delivering a truly next generation video experience that in the right conditions is mind blowing. The introduction of HDR displays (HDR) is as big an advance, for the filmmaking and television industry, as the switch from black and white to colour! For the technically minded, a modern camera can capture about 12 stops. On a standard monitor that many stops look flat or clipped. An HDR display at 1 000 nits (nit = a unit of visible-light) intensity has about 14 stops with good contrast and no clipping. A 4 000 nit monitor can show about 20 stops.
Standards
As usual in the broadcast industry, there is a bit of a tussle going on about HDR production standard adoption. The Society of Motion Picture & Television Engineers (SMPTE) published their Perceptual Quantizer (PQ or SMPTE ST2084) standard in 2016. Prior to that the Consumer Technology Association issued the open standard HDR10 Media Profile which was very quickly adopted by a wide variety of companies, which include monitor and TV manufacturers such as Dell, LG, Samsung, Sharp, Sony, as well as Microsoft and Sony Interactive Entertainment, which support HDR10 on their PlayStation 4 and Xbox One S video game console platforms. HDR10 is also being supported by the UHD Alliance for UHD Premium, which apart from the TV and monitor manufacturers, is made up of partners such as DIRECTV, Netflix, Panasonic Corporation, Walt Disney Studios, 20th Century Fox and Warner Bros. Entertainment Premium and is currently leading the race as being the most widely accepted way of mastering, distributing and viewing HDR content.
Earlier this year Samsung and Amazon Video announced the release of HDR10 Plus, an open and royalty free standard that Amazon Video have adopted, offering more accurate frame by frame dynamic range adjustments. BBC and NHK jointly developed Hybrid Log-Gamma (HLG) which was very quickly adopted by YouTube and Freeview Play and is 100 per cent compatible with Standard Dynamic Range (SDR – normal HD and 4k). Technicolor and Philips jointly developed SL-HDR1, a clever algorithm set that allows for HDR rendering on HDR devices, and SDR rendering on SDR devices using a single layer video stream and finally, Dolby Laboratories developed an HDR format called Dolby Vision. Out of the many HDR systems currently available, Dolby Vision is probably the most well-known and perhaps more future proof, but it may not be the HDR standard with the most content. Like all the HDR formats Dolby Vision is a proprietary format and it requires you to have a HDR set that has a built-in Dolby Vision decoder. Dolby Vision supports a 12-bit colour depth (68 billion colours) and its compatible HDR TVs are four times brighter than most other current HDR sets and, is heading up the Ultra HD Blu-ray disc market and many streaming video services.
HDR Production
Creating HDR content relies heavily in the way scenes are lit, with increased contrast, broad range of colour and more importantly the ability to have both details in the depths of the shadows and specular spectral highlights. Capturing the full range of these means you need a camera that has the ability to shoot in a Log format, and record UHD. Many of the top brand camera manufactures have HDR cameras well nested in the market – including Arri’s Alexa and Amira family, the range of Sony CineAlta’s (F5, F55 and F65) as well as their FS range like the FS5, 7 and FS700. Of course, RED’s Epic and Dragon are well into it as is Blackmagic Design with their URSA and Cinema cameras. The sensors in these cameras all claim up to 15 stops of dynamic range which is getting closer to the dynamic range the eye can see.
Dedicated HDR post-production tools have emerged with the likes of Adobe Premier Pro and Avid Media Composer leading the field in consumer post-production. The latest version of Adobe’s Premiere Pro CC has greater support for HDR video, as well as the Rec. 2020 colour space. There are extra Lumetri Color control panels for handling HDR footage and the application offers a HDR specular colour wheel. Adobe has said that with a supported external HD monitoring system, RAW camera formats alongside the Dolby Vision codec, can be edited and graded with much greater dynamic range than conventional video, by using the HDR controls.
SGO’s Mistika colour grading and post-production system, deployed on films like The Hobbit trilogy, also supports Dolby Vision. DaVinci Resolve from URSA manufacturer Blackmagic Design is another option. Due to its wide native camera file support, users can edit and grade directly from the wide dynamic range camera originals. FilmLight’s range of solutions all deliver HDR content. These include the FLIP image processor for on set checking of HDR camera capture, the Daylight system for dailies and transcoding, the Baselight colour grading system and Baselight Editions, which bring the Baselight toolset directly into the Avid Media Composer, Avid Symphony and Nuke pipelines.
Delivering UHD Premium HDR content to the home is still quite far away. Beyond the infrastructure upgrades needed in filming, mastering, and delivering a UHD HDR video, there’s the problem of legacy HD and UHD TV sets that don’t support HDR. But it is refreshing to find that HDR is one of those technologies and innovations that won’t need any heavy marketing for it to be accepted by the end user. Once you glance at a HDR TV screen you won’t need any convincing that images look much better, fresh and exciting. 3D was an amazing technological but short-lived fad, 4K and 8K definitely make things look crisper with more detail, but HDR images with higher latitude, larger colour gamut and higher contrast create more lifelike images, or put simply, makes things look WOW! The only question is, how long will it take before UHD Premium HDR becomes the norm?
