Colour Management

[Petros Nousias]

The reason I was going for the eizo instead of the cinemadisplay is because ive read that its far more accurate. Any thoughts on that?

 

[Graeme Nattress]

X'Y'Z' was chosen to avoid the need for metadata to describe the source RGB space, rather than for computational efficiency.

If you have a reference R'G'B' with known 3x3 transform to XYZ and a white point, it would be:

R'G'B' -> (lut) RGB -> XYZ -> Transform white point if needed -> Target RGB -> (lut) target R'G'B'

with DCI it's

X'Y'Z' -> (lut) XYZ -> Transform white point -> Target RGB -> (lut) target R'G'B'

Graeme

 

[GlennChan]

1- I think the problem with R'G'B' is not because you need the metadata, but because R'G'B' isn't wide gamut.

2-

ICC profiles would be useful for that second problem, though, the mapping of that X'Y'Z' space to the display device. It would be been nice to have a standard approach to this based on a widely deployed technology, instead of leaving the whole thing up to device makers.

I think the problem with ICC profiles is that the LUTs are all in LAB space, and that LAB is too computationally expensive for video work.

2- The other aspect of DCI is that you don't really need a standard on the color management end. If you implement some proprietary color management system, that won't affect interchange with other users.

So suppose you have a projector with six primaries (I think TI has something like this). The additional primaries help extend your color gamut.

You could implement your own color management system, where you have 3 primaries in (DCI/X'Y'Z') and 6 primaries out (the projector's primaries).

 

[Graeme Nattress]

R'G'B' can be as wide a gamut as you want - just depends what you pick as your primaries. XYZ gamut is as wide as it gets, but can't be monitored. Camera gamut is again, less than XYZ.

Yes, LAB is computationally intensive. ICC PCS is XYZ D50, and ICC does spec RGB -> PCS (XYZ) -> RGB without going near LAB though.

You can allow the projector to convert to it's R'G'B' from XYZ via it's own method whether you give it R'G'B (in a known space) or X'Y'Z' with white point E. The difference is really metadata.

I see the DCI "point" about metadata, but seeings as the rest of the format is totally reliant on metadata, it's mad that they use the "no need for metadata" as a reason for the colour space for encoding.

Graeme

 

[Mark L. Pederson]

Lots of anti-DCI feelings building in the industry - especially overseas -

The whole "academy screenings" only in DCI equipped theatres - was a giant disaster in NYC -

I don't thing the jury is out yet on the "real future" of digital cinema in terms of exhibition -

 

[Graeme Nattress]

For one, it's got to be cheaper, easier, and designed so that "everyone" can be part of it. DCI specs, to me, are a compromise, and that they're really designed for film scanned to a DI, rather than digitally originated material.

 

[P Andersson]

zodiac

zodiac

zodiac cinematographer savides in an interesting article

Savides was asked to create a series of templates such as Day Exterior, Night Exterior, Day Interior, Night Interior — which he refused to do. He explained, “I couldn’t look at them. I didn’t want the look-up tables to bias my eye. I wanted to work with a neutral slate, and that neutral slate had to be that RAW file. It’s the only way I could understand what I was doing everyday. The look-up table would slant you toward whatever you made that look like"

or

“He’s amazing. I don’t think anybody could’ve done it this way. David had to figure it out on his own, and then present it to the studio. He had to do smaller projects, commercials. He’d been using the Viper, got really used to it. So by the time I stepped in he had gotten the Viper integrated and he’d figured out how to make the camera work. When I got there, 90 percent of the problems had been ironed out. I was just part of the creative solution.”

http://www.filmmakermagazine.com/winter2007/line_items/there_yet.php

 

[David Kirlew]

RSR is definitely more reasonable... and it's quite a flexible product (though I'm not sure if it works with NLE's... I'm in contact with them now about that).

Still, though, by the time you purchase a probe and the necessary components, I've paid twice as much to calibrate my display as I have for the NLE suite itself...

Am I asking too much for this to be part of an NLE? Or, at least, for software that's in the hundreds per seat, instead of thousands?

Trevor, check out Color Symmetry at www.colorsymmetry.com They are reasonably priced, and I've been in talks with them on a project I'm in talks on. Color Symmetry has direct support with 3D apps and I've been talking with them about support for different NLE's (the three A's).

 

[mezmo]

I think Chris nailed the crux of the biscuit with his analogy to desktop publishing and the concept of barriers being broken from the bottom up. The devotion to established color management strategies might persist in the high end of the market but beyond that forget it. IMHO tape to tape color correction will go the way of the dodo.

Properly set up rooms operated by talented specialists for top quality audio mixing and color grading will still have a place anytime there is a bit of budget and/or quick turnarounds. The real sea change here is that with the maturation of the commodity NLEs (particularly Final Cut) you'll get the ability to get very close to the same finish quality.

We need robust file formats that support higher bit depths and are easily interchangeable. The RedOne > RedCine data centric approach may not be fully supported on day one but given time I expect it to be a very smooth ride into NLEs that are ever more fully featured.

For my part I have painted the walls 18% gray, added some medium gray acoustical panels, spent a little coin on some near field optimized speakers for audio mixing and am ordering an eCinema DCM23 monitor for color grading. I may not be able to match the talent of the best post houses in LA or NY but if Final Cut Studio 6 includes a 10 bit color correction engine...

... and the walls came down, all the way to...

I don't know Blair,
Getting an editor to colorgrade is a bit like getting a vet to do your
dental work.
much pain involved.
Mezmo

 

[Joe Carney]

The reason I was going for the eizo instead of the cinemadisplay is because ive read that its far more accurate. Any thoughts on that?

Petros, I'm looking at them too. They have hardware based color correction (on board monitor..) 12bit lut and 16bit processing.
I've been looking at this one...
http://www.eizo.com/products/graphics/cg241w/index.asp

and wonder if it couldn't be programmed to give the 'look' you want.
I wouldn't use an Aja either, just a quadro fx or FireGL. Seems for those on a budget, a reasonable solution for playback/preview. (2 monitor system).
My goals are Broadcast, Blu Ray and Internet. When I shoot 4K it will be downrezzed to 2K or 1080p for everything.

 

[M Most]

My goals are Broadcast, Blu Ray and Internet. When I shoot 4K it will be downrezzed to 2K or 1080p for everything.

In that case, you'd be much better off with a broadcast type monitor (as opposed to a computer monitor), as that is already displaying Rec709, which would be your base color space for both of these applications, and thus does not require the types of calibration you're talking about. Of course, you will need to feed it HD video, so you'll need a card for that (either a Kona or a Blackmagic will do).