Expanding the Range of Video Production with HDR
Senior Production Manager
The video production industry is anything but stagnant. Technology, to the delight and dismay of studio owners, seems to change as soon as the latest generation has been adopted and standardized. You can’t talk about 4K without mentioning 8K. And now, you can’t discuss either of those without mentioning HDR.
The move from HD to 4K and eventually 8K is, among other improvements, a significant increase in resolution—more pixels. HDR is not another resolution boost. In fact, HDR is reliant upon HD, 4K, and 8K for final output. It can be produced in HD, 4K, and 8K, but can provide better quality within the current HD and UHD standards.
Simply put, the promise of HDR is better pixels—more information within a given resolution and display format. The result is an image with greater shadow and highlight detail as well as greatly expanded luminance and color gamut (REC709 vs. REC2020). Images are richer, more life-like, and more cinematic. These qualities lend HDR to entertainment and theatrical productions. As the technology evolves, its uses will likely expand.
HDR, like every other production standard iteration, has a significant impact on how production and distribution are handled. It’s important to note that at this time the industry has not adopted a universal standard for HDR. There are multiple methods in various stages of development and operation. HLG (Hybrid Log Gamma) is an open-source technology used by the BBC and NHK in Japan. The HLG format can be used in live scenarios and is compatible with standard dynamic screens, but has a reduced effect. Dolby Labs has developed its own standard called Dolby Vision (SMPTE 2084), which produces true HDR, but cannot be used in live productions as of yet, partly due to the significantly increased file size and metadata demands.
Increased file size certainly is not exclusive to Dolby Vision; larger file size is a consideration for most HDR formats due to the amount of information gathered during the HDR production process. Current estimates indicate at least a 20% increase in bandwidth consumption for HDR files.
Due to increased bandwidth and file size, it is critical to know the desired end result, how it will be displayed, and how it will be delivered at the start of production. Is it intended for broadcast, theatrical and cinematic presentation, or on displays in consumers’ family rooms? In some cases, two files may have to be rendered (standard dynamic range and high dynamic range), depending on the needs of the final product.
Footage has to be acquired in formats compatible with HDR, as it is fairly restrictive in terms of file and format compatibility due to the amount of information required to render HDR. Files such as 10-bit 4:2:2 files are compatible, but older, compressed files likely are not compatible. Knowing this at the outset of production will inform many decisions about capture and post-production, and simplifies overall production.
The fundamentals of production are unchanged by HDR. The same principles of lighting, sound, blocking, and camera operations still apply. Where HDR has a significant impact is in post-production, an impact driven by larger file size and the necessary color grading specific to HDR. This is where the cost to produce HDR will increase, simply due to the increase in time required to edit, color correct, and render the larger files.
A Mark Along the Continuum
Advancement in HDR is more than “one-upping” 4K and 8K. On a scale of 1-10, HDR advances ever closer to the mythical “11” videophiles and audiophiles ardently seek. Eleven is an unattainable number on the scale, but is always the target with every improvement in technology. HDR is perhaps the most significant improvement of late, given the leap in image fidelity and detail.
WestWorks Studios is excited for the arrival of this new technology. It is too early to be offering HDR as a production service, but that’s not stopping us from testing and experimenting. As the standard becomes defined and processes streamlined, expect HDR to become more available and efficient.