LUT for Lab

[Abd Samad Hassan]

Hi Red gang,

We're trying to finish a project on Color, just one question;

How do we make sure that whatever the grades and output of Color, matches the output that the film lab print out for us?

Is there a calibration process that a post-house has to go through with the film lab?

Thanks,
Sam

"Your game is like horse poo" - Coach Q
(From the film Hooperz, shot on Red)

 

[John Tissavary]

The short answer is "yes", but the specifics will vary based on who the lab is and what your equipment setup is.

This is a rather complex process and will benefit from someone with experience in filmouts from digital files.

If you are grading in a DI theater with a Christie or Barco projector, then it should be fairly easy to match. You may already be grading in P3 color space, and many modern labs can do a fantastic job with the filmout from P3.

If you're grading on an 8-bit LCD monitor it will be more difficult, and experience seeing the results of your work from that monitor on film can help you 'feel' out the inevitable out of range values that cannot be remapped from film to a monitor via LUT.

Your best bet is, in any case, to do a series of short 1 minute tests, then create your own LUT by eye to get your monitor to reproduce what is on film from that specific lab as accurately as possible, though the film will not fit 'inside' the monitor.

Also: determine what your lab is good at shooting to film - rec709? P3? pdLog? Look at their results so you can decide where there strengths are in color science. Then you can work in that chosen space to get them the images that will best translate onto film. This, too, will require tests. Bottom line - you can never have enough 1 minute filmout tests.

Let me know if I can be of any further assistance, as I do this fairly often with hardware and software setups of varying configurations.


cheers,

John T.

 

[Abd Samad Hassan]

John,

Thanks a lot. We've just sent out a series of 1 minute tests out a few minutes ago for kine. It's a feature shot on F-900 and graded on Color.

Just one question though.
Would it be better to generate luma and chroma swatches out from Color and try to get a lab to match that,
Or
To ask the lab to provide their swatches so we'd match that to our Color. Will that work? Getting our lab to do that would cost more than buying Cinespace but if it syncs our output then it'd be worth it.

Thanks,
Sam

 

[John Tissavary]

I think you'll want to control color science at both ends, but you'll have the most control on your own equipment, in my experience.

Cinespace is a great way to go, I highly recommend it. You can create short filmout tests to project in a typical theater setting & sample with the probe to build 'cubes' from, and you'll need to do that for each stock you're using.


regards,

John T.

 

[Ido Karilla]

see this:

http://www.reduser.net/forum/showthread.php?t=18545

With very limited resorces I got now a monitor that desplays the film out result accuratly.

It is not a simple task and you have to have somone with the "know how" to guide you through.

Ido.