Color Gamut and HDR

[Elias Dinter]

Hi,

First I want to ask you to be a little bit forgiving for a newbie like me. Besides some little consumer toy cams I have never owned a cam in the prosumer segment in the last decade. But this is going to change, soon. :-) I am planning to invest in a system such as a Canon EOS C100 Mark II, Panasonic GY-LS300 or even lurking at a Sony PXW-FS7. I am planning to use one of these babies for documentary and wild expeditions. So it has to be both compact and light but also robust and enduring for everyday usage. And of course it should deliver beautiful pictures. :-)

I don't want to make this thread a discussion about which cam is the best, I can read the specs and other user's impressions myself. By the way, thanks for all sharing their thoughts! Having a strong background in display and video reproduction technology I was able to figure out a lot of my questions on my own.

Nevertheless there are some points I need your advice: As we all know the industry is moving to UHD these days and I am quite confident that this shift will influence the way video will be presented in the next decade. But for me the increased resolution is not the most interesting change. For my planned projects it is much more important that the system is able to hold the focus as a slightly out of focus image will instantly stop any debate if a 4K resolution is beneficial for a TV presentation. Don't get me wrong, higher pixel count is always a benefit per se, you can choose to downscale the image anyway (i.e. for post processing). On the other hand what you have missed to capture is lost forever.

But there is an enhancement in the works I am really looking forward in the future... HDR video and extended color gamut. With the new Blu-Ray system around the corner and even streaming media adapting this innovation TV manufacturers already have started to introduce this technology to the consumer. The specifications for the upcoming BD are already an open secret. At least 10 bit luminance resolution and a color gamut up to BT.2020.

Surprisingly there is not that much discussion about these two issues, at least I am not aware of it. I assume current gen cams are not perfectly fitting for these upcoming demands, but reading the specs I am even more surprised to not find any clear technical detail regarding these issues.

Therefore I am wondering what is the state of art when considering camera systems up to 10K. What is the best and future proof device regarding this aspect?

Thanks for all your comments!

[Bryan Cantwell]

Future proofing doesn't exist in this industry. :)

[Brian Drysdale]

The future proofing is having content that people want to watch. People still watch 405 line B & W TV programmes from the 1960s.

[Seth Bloombaum]

Originally Posted by Elias Dinter

...Therefore I am wondering what is the state of art when considering camera systems up to 10K. What is the best and future proof device regarding this aspect?

If acceptance of 4K and future up to 10K is important to path in these industries, that is, you'd like to be in a position to use this tech on a sustainable basis, you should consider how you can support getting a new camera at least every 18 months, and a new editing system every 36 months or so, with lots of small acquisitions, too.

If the past is any guide, today's baby steps towards 4K shooting, editing and distribution will seem pretty quaint and backwards in 3-5 years.

Most working pros that I know rent gear as much as pencils out, buy the best they can when they have specific needs and future projects lined up, and resign themselves to lots of upgrades.

It's all a moving target. The trick is to stay in business (keeping expenses in line), and not be locked into yesterday's tech when you need today's solutions.

[Bryan Cantwell]

Originally Posted by Brian Drysdale

The future proofing is having content that people want to watch. People still watch 405 line B & W TV programmes from the 1960s.

We're currently airing movies dating back to the 20's and 30's, and people are definitely watching.

[Elias Dinter]

Thanks for the advice! I fully understand that we are talking about a moving target.

Updating the equipment regularly is definitely a good idea. On the other hand, when you have to buy now, you have to choose the best option which is in your budget.

For me the new color gamut and the HDR feature are really attractive, therefore I am wondering which model to choose for matching these criteria best.

Thanks!

[Jon Fairhurst]

Hello Elias,

I think the key is to be able to record RAW. That will preserve the maximum dynamic range and color gamut available from any camera.

Regarding workflow, consider ACES. It can handle a dynamic range of 30 stops(!) and is non-destructive. One could stay in the RAW domain, but this means that the editing system has to do live de-Bayering, which is resource intensive. By decoding RAW to ACES, one has a general format that can be used for various cameras, graphics, etc.

There are three big challenges on the output side: monitoring, delivery, and the final display. There are few HDR monitors today and they are priced at the very high end. 4K BD is not here yet and there are no online delivery platforms established for HDR video. Finally, there are no compatible HDR consumer displays. Yet.

In any case, by shooting in RAW and editing in ACES, one would be prepared for HDR delivery. Sony Vegas supports ACES; however, some years ago when I used their floating point option (which is possibly related to their ACES implementation), the results on my computer were quite slow. Their newest software might be more efficient and, of course, modern computers are more powerful than my 2010 machine. In any case, you might need a powerful computer with lots of RAM and an optimum video card for good results.

Here are some ACES resources:
ACES | Oscars.org | Academy of Motion Picture Arts and Sciences
Academy Color Encoding System - Wikipedia, the free encyclopedia
ACES in 10 Minutes ? NegativeSpaces - Ben Cain
http://dspcdn.sonycreativesoftware.c...s_workflow.pdf

[Jon Fairhurst]

An additional note about using ACES, though I haven't used it myself...

The exposure in ACES is "scene referred" to mid gray. Also, note that RAW leaves the color temperature to be chosen later. ACES has a fixed color temperature (though with so much dynamic range and color information, that one can still do extreme grading.)

I believe that the best practice is to shoot a gray card before each shot (or set of shots if the light isn't changing.) When transforming from RAW to ACES, one would set this as the mid-gray reference point and use this (or a white card) for color balancing.

Note that this would be for typical situations only. If you know that the gray card is the darkest item in your shot, you could effectively expose ACES to a lower level, allowing more bits above mid-gray. If it's the brightest item, expose higher, allowing more bits in the shadows. Then again with something like 15 stops above and below, it's unlikely that ACES can't handle all of your camera's range, regardless of where mid-gray is in your shot. The only reason to expose ACES higher or lower would be to get a nice looking result immediately before any grading.

The color balance situation is similar. One would typically normalize to the gray card, but that might not meet the artistic intent. For instance, if one color balances for a sunset shot, the sky will be blue. If you used a fixed color temperature of, say, 6500K, the sky will be orange as intended. Similarly, if you know that you want a specific artistic look, one might color balance with a red/green/blue bias as desired. That said, if nothing else, the gray card will provide a reference point to which you can apply a consistent offset, so it's not a bad practice to bring one along.

Note that this is different than the camera exposure. One might expose to the left when bright details are the most important and to the right when the shadows have the most value. This optimizes your shooting range. By normalizing the transform to ACES using a gray card, everything will cut together quickly and naturally. You can then squeeze the shadows and/or highlights as necessary to get things in the viewable range, but the face tones will be roughly correct before any adjustments.

For nature shoots, I can picture bringing a fishing pole and line. Put the fishing pole in the ground with a gray card on it in front of the camera. Start shooting, then pull the pole down with the line. That would be lightweight and would allow solo shooting. :)