At the moment HDR (High Dynamic Range) is a big buzzword in the cinema world, for a couple of reasons:
- it is available on TV, sets are available at your local store, and it’s the first time in history that picture wise you can get something at home you can’t have in your theater.
- Well, actually you can. There’s Dolby Cinema, and it’s amazing. But it requires a special projection setup and a pitch black room with a special (great) design. For my own little case, none in France and getting to the closest one is probably a 4h train ride… I wish I could do it more often! And when you catch one, you don’t have much choice as for the movie.
- Imax also proposes HDR on a couple of their screens.
- EclairColor, our proposition at Eclair/Ymagis, with a different approach, designed for a larger market share and not so much focused on the very high-end, is picking up.
The creative opportunity is fantastic. One of the most important thing that comes with HDR is the fact we don’t use the peak brightness of the projection system as the diffuse white reference; say you have a white car in the scene, the luminance between the HDR version and the SDR version would pretty much the same, until you want to create an effect. You’d rather avoid using a value set too high for diffuse white in a dark environment, because then you start to see flickering: the human visual system needs more frames per second to rebuild the motion when you have more light (we’ll discuss HFR, High Frame Rate later, I love it). So you keep the white at the same level, but you use the extra light provided by the system to reveal finer details, those that are usually clipped or compressed in the standard version: details in hair, smoke, clouds, but also textures, specular reflections, etc.
On this picture from “Belle et Sebastien, l’aventure continue” we can see more depth and vibrance in the EclairColor HDR version (relative simulation)
The human visual system is not only about the eyes and the brain does a lot of work processing the image, where contrast and definition are hard linked together; when you bring more contrast, it feels like there is more details. Also the fact that you can reach much brighter colours on their peak value while keeping white reference the same as SDR gives the sensation of super rich colours with extra nuances and depth, because the brain rebuilds the scene out of the relation between colours.
As a big fan of film, there was always something I thought that was missing in digital, some depth in some particular colours. With HDR I have the feeling that we finally bridge the two together, and most of the DoPs I talk with agree with that. If you need to be convinced, you should see La La Land in EclairColor, probably the best example I’ve seen so far! Some DoPs are afraid because they don’t want their movie to become flashy while they set their picture for a delicate look; but as for colour or sound, it’s an extra tool in the palette : you may want to use the extra depth for one shot or one pixel, or paint your whole story with it.
So HDR will be everywhere on next CinemaCon, because this is clearly the future. HDR for all cinemas: all screens, all movies. See you there!
Cedric
PS: For those of you who want to get deeper about colour and perception, you can check this great article from an HPA retreat conference in 2014 about gamuts, colour cubes, HDR and curves. There is a lot to say about colour and I’ve spent a lot of time over last 15 years talking about it. The more I do, the more I love it!
PS2: EclairColor is more than HDR, find out at www.eclaircolor.com
Images courtesy of Gaumont and Globo Filmes
Originally published on Linkedin, February 2017