From postPerspective:

Quick Chat – FilmLight CEO Wolfgang Lempp on HDR

FilmLight, creator of the popular BaseLight color grading system, has been making products targeting color since 2002. Over the years they have added other products that surround the color workflow, such as image processing applications and on-set tools for film and television.

With high dynamic range (HDR) a hot topic among those making tools for production and post and those who believe in HDR’s future, we reached out to FilmLight CEO and co-founder Wolfgang Lempp to pick his brain about the benefits of HDR and extended color gamut, and what we need to do to make it a reality.

Are you a fan of HDR?
Definitely. It opens up more creative possibilities, and it adds depth to the picture. Not everything benefits from looking more real, but the real world is certainly HDR. There is a certain aesthetic to dim highlights, as there is to black-and-white photography, but that is no justification to stick with black-and-white television, or with dim displays.

And consumers will appreciate the benefit of HDR too. When they walk into an electronics store and see a couple of HDR televisions among the standard screens, they will leap out as being clearly better. That is very different from stereo 3D technology, and it will drive the adoption of HDR in a big way.

So, what will it take to get HDR to consumers?
High-end cameras have been HDR for quite a while. It is just that we have compressed the output to make it look okay on standard displays. We now have the displays, and we are starting to get the projectors, too. The biggest obstacle is the infrastructure in between, and the implications regarding the proposed standards.

So there will be a time of confusion, as well as a time for bad HDR, before the dust will settle. And sadly, like with 4K and UHD, we probably end up with two different standards for film and TV. The big question at the moment is whether the least disruptive method, which uses the same signal for both standard dynamic range and HDR displays, will be all we can realistically hope for in TV at this point, and whether that is actually good enough.

Is the SMPTE PQ standard the answer?

SMPTE 2084 — which formalizes the Dolby Perceptual Quantization (PQ) concept — is already in use and has its merits, certainly for movies where you can send the right version to each cinema. But it is a bit too forward-looking for the broadcast industry, which prefers to send a common signal to both standard dynamic range and HDR displays at home.

The existing broadcast infrastructure can be made to work with the current generation of HDR displays, and that might well be good enough for many years to come. SMPTE PQ is looking further into the future, but ironically the projection technology for cinema is trailing behind in terms of absolute brightness, so for the foreseeable future there is even less of a need to provide for that extra dynamic range.

The critical issue in the short term is banding of contours, not in the very dark parts of the image which we are all familiar with, but in the mid-range. PQ is the safer bet in that respect, but it needs a higher bit depth than the broadcast distribution channels are offering.

BBC in the UK and NHK, the Japanese national broadcaster, have put forward a proposal for a hybrid logarithmic and gamma encoding that could be a reasonable compromise for broadcasting, but it remains to be seen if it is a compromise too far when a wide variety of HDR content becomes available. It would be a shame if we end up with a long list of do’s and don’ts to make the images look acceptable.

At FilmLight, we support both standards, and if the industry can agree on something better, we will of course support that too. Our interest is in taking the technical limitations away from post and allowing people to concentrate on creativity.

What happens when an HDR signal reaches televisions in the home?

The real concern is set up — because to see the benefits you have to set things up correctly. And a relatively subtle shift, like extended color gamut or a not-so-subtle shift like HDR, has the capability of being badly configured.

When we moved from 4×3 to 16×9 displays, many people didn’t bother to adjust the screens correctly, so 4×3 content was stretched, making everyone looked squashed and fat. Even today, that problem hasn’t gone away completely. Whatever system is in place for delivering HDR to the home, it has to be simple to set up accurately for whatever receiving device the consumer chooses to use.

Some colorists are expressing concern about working with HDR and eye strain. Is this a serious issue?

The real world is HDR. Go outside into the sunshine and see what extended color and dynamics really means. The new generation of displays deliver only a pale imitation of this reality. Our eyes and brain have the ability to adjust over an amazingly wide range.

The serious point is that HDR should help to create more realistic, as well as more engaging and enticing pictures. If all we do with HDR is make the highlights brighter then it has failed as an addition to the creative toolset.

Colorists today are used to working in a very dim environment. It will be different in the future, and it will take some time to get used to, but I think we all have faced more serious challenges.

What do you think the timeframe is for HDR?

It is already happening. Movies are out there and television is ready to go. NAB 2015 saw the gee-whiz demonstrations and NAB 2016 will see workable, affordable, practical solutions. January’s CES featured many HDR-ready displays on show, so there is real pressure on the broadcasters to provide the content.

If it is used carefully and creatively, I am very excited by the prospect, and I believe viewers will absolutely love it.