HDR Television – What is it, and Why Should My Video Production House Care?
*Any images showing HDR here (or anywhere online) are just an approximation. You can’t view HDR unless you have a HDR capable display.*
The next big adoption in display technology is going to be High Dynamic Range televisions. Camera manufacturers and post companies are developing workflows and monitoring paths so content creators can deliver quality films and shows to view. This is going to be a far more significant development for production professionals than 4K displays have been.
First I was a bit confused, mixing up the terminology known from the camera side of things HDRi with the display technology HDR. One has little to do with the other as we’ll see explained below.
Essentially what has to be known is that HDR technically has zero to do with the camera that you shoot with, and everything to do with how what you capture is displayed. A standard Rec.709 display can show approximately 7-9 stops of dynamic range (In my research I’ve seen numbers as low as 5 stops, but you get the idea). Almost every camera used these days is boasting at least 14+ stops of range. The real work in creating HDR content is what happens after the shoot wraps and you head into post and into the color suite. Because we’ve been acquiring footage with information beyond what Rec.709 could natively display for many years, what you are shooting today is already HDR ready. You just need a workflow and a way to monitor.
First in the HDR equation is brightness, usually measured in nits. Standard LCD/OLED televisions & production monitors fall somewhere between 120-500 nits of brightness. Dolby’s touted HDR monitor, Pulsar, tops out at 4,000 nits. This is not just about the brightness of the image displayed but extending the highlight details within the brightest parts of the image. Dolby is suggesting 4,000 nits as a starting point for a standard, and upping it to 10,000 when the display technology catches up.
The benefit of the wider range of brightness can be thought of using a sky as example. On a normal SDR monitor, you can push the brightness of the blue sky only so far before all channels reach maximum, and you return white values. In HDR, you can continue to brighten the sky and keep a blue color. Similar benefits to reflections, fire, explosions.
The second benefit is a wider color gamut. (This is not technically required for HDR, but is going to go hand-in-hand with the future of display.) The Rec.2020 specs have a color gamut so wide that there is no display in existence (yet) that can show all colors in range. The closest you can get is laser projection, and I don’t know of an example of anyone grading specifically for that. Even UHD specs call for only 90% of P3 colorspace as a qualifier to be labeled UHDTV. In a hilarious twist that 90% coverage is about the same volumetric space of Rec.709.
The Rec.2020 spec isn’t really critical, as most things you see in ‘normal’ conditions can be prefectly rendered within our existing Rec.709 colorspace. The real advantage of the wide gamut will come into play with extreme color grades, and when filming lighting sources such as neon and LED. Rec.2020 exists for future proofing, and will allow for new tech to take advantage of the information that will be available in the footage.
In the upcoming year we will see more HDR content being released as TV manufacturers try to stay on the leading edge of the technology. And HDR masters will probably be the domain of Hollywood & other big budget commercial shoots for a time. But I think it is pertinent for any production house to begin following the workflows and begin to be educated on how to deliver footage so that they can stay ahead of the curve.
And colorists, please for the love of shit don’t make all of your footage look like this:
I’m pretty sure we’re going to see a lot of ‘everything exposed in the middle’ in the early adoption period of HDR. Go to a store and see the demo footage playing on a HDR TV. It is visually exhausting, and in my opinion not very filmic.
In my next follow up I’d like to take a look at setting up a HDR workflow within Resolve. Thankfully it is pretty painless. The most painful part is getting a monitor to grade on.