Digital Cinema - Projector Settings... Color Correcting... Help!

[sbrookens]

Hey All,

Question:
What is the best way to color correct a film/video for display on a digital cinema projector? (We use FCP and Color with Wraptor plugin for encoding).

Background Info:
We are doing a showing of our Red Demo Reel at a local theater next week on a 2k projector. We did this last fall and the image just didn't look that good. We discovered quickly that the world of Digital Cinema is completely different than the DVD world that we are used to. The colors were off and the image looked really dark on the screen. That being said, we really want it to look perfect this time around. I just talked with the projectionist and he gave me these settings from their projector:

color space - Unity RGB
target color - DC28 DCI XYZE 314 35
gamma - 2.6
data format - 444 PAC 12 bit

We use the Wraptor plugin for Compressor from bankrupt QuVis to encode our sequence to JPEG 2000. Basically, what we want is for our demo reel to look the same when projected as it does on our computer screens. How can we make sure that happens? We can't recalibrate the projector - theater won't let us. So can we calibrate out color correcting monitors to be the same as the projector? Any other ideas?

Thanks in advance!

 

[Blair S. Paulsen]

There is a really good way to do this using a transform called a 3D LUT (look up tables) where you create a target LUT profile for your monitor that will mimic what the projector will show. If you have a few bucks, Steve Shaw at Light Illusion should be able to hook you up.

If you need to do this yourself, and can deal with much better than before - but still a step away from dead nuts on - then here is my suggestion:

take some footage you know really well and make a dozen different versions of it. Choose maybe 4 different gamma settings to get a handle on what gamma on your source will display well on their projector.

If you are used to working in rec709 (HDTV color space) then the move to XYZ is a bit of a shock - it is a bigger color gamut and has different characteristics. The full explanation of each of the major color spaces would require a couple of books and if you want to learn about it, get your hands on some.

My "roll your own" plan is much more of a trial and error approach. If you have or can borrow a MacBeth chart, you could use that - if not then use footage you know well and use that. Try a bunch of different settings and transforms available in the software you have. Note which is which.

Go over to the theater and see your tests with your own eyes. Make notes. Make the best final you can.

I am not saying this is the "best" way, just that it is cheap, practical and has the advantage of being targeted to the specific theater/projector you will be using. If you need it better then hire a pro. Proper color management is part of how the top dogs differentiate themselves from everyone else. If that is the sandbox you intend to compete in then forget the shortcuts and do it right.

Cheers- #19

 

[Noah Kadner]

Can the projector manufacturer send you a basic LUT? That would help a lot.

Noah

 

[sbrookens]

Blair and Noah - thanks for your responses! I really appreciate it.

Blair - Thanks for the different ideas/solutions. For this specific presentation we are looking to keep it on the cheap. BUT, we do want to learn how to do this like the pros do for future projects. Any suggestions on what I can read to learn more? Also, thanks for the reference to Steve Shaw. Where is he out of?

Noah - I called Christie, the projector manufacturer, and all he could do was e-mail me some info about how to calibrate the projector... Great idea though!

If anyone else has other ideas keep them flowing! I really appreciate the help!

Thanks!

Scott

 

[Blair S. Paulsen]

Steve is over in the UK but there are plenty of people versed in color management and LUT applications like what you need. I only mentioned Steve because he is extremely good, and, he shares a lot of information with the community - which I really like. In fact, the link below and his entire site is a storehouse of valuable info.

http://www.lightillusion.com/usingluts.htm

I do not have any financial interest in Light Illusion but wish I did :drool5:

BTW - If anyone on the forum has read enough different books on Color Management and LUTs to make an informed recommendation I would pick up a copy myself. Most of what I have learned is from manufacturer driven texts that tout why their particular solution rocks. A neutral overview of the subject would be a treat.

Cheers - #19

 

[M Most]

Basically, what we want is for our demo reel to look the same when projected as it does on our computer screens. How can we make sure that happens? We can't recalibrate the projector - theater won't let us. So can we calibrate out color correcting monitors to be the same as the projector? Any other ideas?

First of all, if you're color correcting by looking at a computer screen, all bets are off. If you're looking at a monitor, being fed by a video output card, then at least you have a reasonable starting point. What needs to happen is that you need to take your material that was corrected for (I'm guessing) Rec 709 HD video and use a 3D LUT to get the equivalent colors in P3 color space. You then need to view that on a monitor that is set up to emulate P3 and 2.6 gamma. At that point, you can render out a DCDM (consisting of 16 bit TIFF files) and from that, you can create a DCP. If you're using Wraptor, it supposedly does the color space conversion for you, but unless you've been looking at a proper video monitor, that's not going to be correct.

Having said that, my suggestion would be to take the reel to a facility that does this professionally and have them do it. It sounds to me like you're in way over your head here, but it also sounds like the piece you're trying to convert isn't that long, so the costs involved would likely be rather minimal. You can keep experimenting and guessing from today until doomsday, but if you don't understand what it is you're dealing with it's all a waste of time.

 

[jake blackstone]

How long is the piece and where are you located? If you're in LA, I may be able to help.
Oh, never mind. Just saw, that you're in Grand Rapids, unless you'd want to overnight it.

 

[jake blackstone]

Steve is over in the UK but there are plenty of people versed in color management and LUT applications like what you need. I only mentioned Steve because he is extremely good, and, he shares a lot of information with the community - which I really like. In fact, the link below and his entire site is a storehouse of valuable info.

http://www.lightillusion.com/usingluts.htm

I do not have any financial interest in Light Illusion but wish I did :drool5:

BTW - If anyone on the forum has read enough different books on Color Management and LUTs to make an informed recommendation I would pick up a copy myself. Most of what I have learned is from manufacturer driven texts that tout why their particular solution rocks. A neutral overview of the subject would be a treat.

Cheers - #19

Blair. You or anyone else, who's interested are welcome to come over for hands on DCI demo:001_cool:

 

[sbrookens]

Thanks M Most for your input-

We admit that we are in slightly over our head, but taking this to a post facility, although ideal, would not allow us the opportunity to learn how to do it ourselves. We are definitely not opposed to hiring various professionals to do what they do best, but if we did that every time we didn't know how to do something then we would be far from where we are today. All that to say, thank you very much for your input! I am not exactly sure what the Color setup looks like, but I think they have a pretty decent monitor. Crossing my fingers!

 

[jake blackstone]

Thanks M Most for your input-

We admit that we are in slightly over our head, but taking this to a post facility, although ideal, would not allow us the opportunity to learn how to do it ourselves. We are definitely not opposed to hiring various professionals to do what they do best, but if we did that every time we didn't know how to do something then we would be far from where we are today. All that to say, thank you very much for your input! I am not exactly sure what the Color setup looks like, but I think they have a pretty decent monitor. Crossing my fingers!

Then, really, never mind

 

[M Most]

Thanks M Most for your input-

We admit that we are in slightly over our head, but taking this to a post facility, although ideal, would not allow us the opportunity to learn how to do it ourselves. We are definitely not opposed to hiring various professionals to do what they do best, but if we did that every time we didn't know how to do something then we would be far from where we are today.

You would learn anything you want to know if you would ask questions of the professionals doing the work. What you need to do is ask the right questions, which means doing some homework so that you understand what it is they have to do even if you don't know exactly how they do it. There are a lot of resources for this, starting with the DCI specification, freely available at www.dcimovies.com. Doing a job with professionals can be the best learning experience you can have if you don't go in thinking that it isn't. If you think you can learn this stuff in a vacuum, or just by asking questions on Internet forums, you're not trying very hard. It's much easier to figure something out once you know how others already do it.

 

[Jakebarnes]

Color problem with Wraptor

Color problem with Wraptor

The colors were off and the image looked really dark on the screen. That being said, we really want it to look perfect this time around. I just talked with the projectionist and he gave me these settings from their projector:

QUOTE]

I am having the exact same problem. I have perfect, color-corrected YUV, but I run it through Wraptor to make a DCP and the output is dark with some color shifts.

Either I am doing something wrong, or Wraptor is converting to this XYZ colorspace the wrong way.

Has anyone ever made a Wraptor DCP that looks right??

What's the trick?

I do not understand why I would need a "LUT" Shouldn't Wraptor know how to make a proper conversion from perfect-looking YUV to XYZ?