High Dynamic Range (HDR) is a hot topic in both production and post, and being considered for a broad range of productions across the board as we dive into 2018. Every new smart phone is supporting it, and Netflix and Amazon are regularly finishing and releasing new programming in HDR and 4K. Currently OTT services are leading the charge in demand for HDR, with sports production coming in a close second.
Netflix’s Unbreakable Kimmy Schmidt
Our customers in production and rentals are seeing a huge demand for HDR support now for on-set workflows. Instead of reworking the middle of the pipeline to feed video villages, these customers are looking into solutions for up-converting signals on the back end. This allows production teams to shoot log files as they’ve been accustomed to; outputting Standard Dynamic Range (SDR) for the majority of monitoring around the set, while simultaneously up-converting to HDR for the director and DP to monitor finer details in the highlights and color on dedicated HDR displays. These kinds of solutions simplify workflows on-set, taking incoming imagery from popular professional cameras and converting their log output in realtime to 4K/UltraHD or 2K/HD and outputting signals as either HDR or SDR. This level of flexibility is essential as workflows are adapted to support the needs of HDR.
The prospects of HDR delivery also pose a new set of creative challenges. Productions need to take HDR into account from the get go, and monitor at least some of the output on-set in HDR to avoid expensive ‘fix-it-in-post' scenarios for corrections on the back end. HDR literally brings more detail to the forefront, with added luminance and color gamuts revealing textured details in make up, set dressing and more, and this increased perception means you need to more carefully monitor lighting balance to composition in a shot— as the eye may be led away from where you want the focus point to be if not closely monitored. It’s simply crucial to have some form of HDR monitoring during a shoot. The flip side of this work on the front end is that the quality of production assets increases dramatically and is easily perceived by viewers. There are many affordable camera choices today that have a wide dynamic range and produce stunning footage; HDR enables more of the dynamic range of their sensors to be delivered to the end viewer — it’s win-win for everyone.
Netflix’s Stranger Things
In post, basic challenges arise, primarily tied to metadata for the different HDR methodologies. There’s static metadata with HDR10, dynamic metadata introduced with Dolby Vision and now HDR10+, and HLG, which doesn’t rely on metadata. None of it is overly cumbersome, but attention will need to be paid, especially when materials are recut and tweaked. These various standards exist to accommodate a range of delivery scenarios, and manufacturer specifications. In live broadcast, for example, you don’t necessarily want metadata because it may go out of sync and create problems, making HLG attractive, while dynamic metadata plays well for scene-by-scene and shot-by-shot creative control needs for episodic and digital cinema needs. Metadata management is something that HDR productions need to pay close attention to, and editorial tools are now seeking to address this with recent software releases.
Challenges aside, pursuing HDR brings content providers and viewers closer to what the naked eye can see through a video display. There are a host of new cameras, monitors and video processing hardware and software that are paving the way by integrating into existing creative workflows. Most HDR productions will use a mix of SDR and HDR displays for monitoring, and with the right combination of hardware and software (such as the Colorfront Engine with AJA FS-HDR), both can be previewed accurately from the same source signal. With realtime HDR and wide color gamut (WCG) processing and conversion, these solutions are there precisely to bridge SDR to HDR, HDR to SDR and HDR to HDR, all in realtime.
Bryce Button is the Director of Product Marketing for AJA Video Systems (aja.com), based in Grass Valley, CA.