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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Lustre's Lut?

raufzaza

raufzaza

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Hi
I've finished color correction for a feature film in apple color, I've worked in REDSPACE, rendered linear DPX files with 0 black 1023 white.
Now I'm doing color correction on lustre for our film out, but the Lustre colorist is using a 3d lut of kodak 2183, and the image is looking a very heavy high contrast version of my image, mid-tones are crushed into shadows, hi-lights are so bright.
what is the correct Lustre 3d lut to work with in my case?
and who figured out to have some luts for apple color.

Thank you, any response might be helpful for a lot of guys arround here.
 
Lustre colorist, I still need your help here.
 
Rauf, if the colorist is expecting a standard DPX file with levels in the standard range, give him that.

Don't try to get them to learn a new Redspace (0-1023) workflow for your job. It'll take them extra hours and they'll bill your for it.

Unless they're your friends and want to learn.

Personally I'd render out the full redspace one and then do a conversion to standard range. Can Color do that?

If Color can't do that, I'd do this: bring it into After Effects, get it looking good to your eye (in linear mode) (using curves etc - DON'T CLIP ANY HIGHLIGHT OR SHADOW DATA), then export with these settings:

black: 95
white: 685
gamma: 1.7
highlight expansion: 20
logarithmic conversion: on

This will make it look roughly right when the colorist brings it in. Then he can move on from there to make it look awesome.

Bruce Allen
www.boacinema.com
 
raufzaza said:
Hi
I've finished color correction for a feature film in apple color, I've worked in REDSPACE, rendered linear DPX files with 0 black 1023 white.
Now I'm doing color correction on lustre for our film out, but the Lustre colorist is using a 3d lut of kodak 2183, and the image is looking a very heavy high contrast version of my image, mid-tones are crushed into shadows, hi-lights are so bright.
what is the correct Lustre 3d lut to work with in my case?
and who figured out to have some luts for apple color.

Thank you, any response might be helpful for a lot of guys arround here.
Click to expand...

If You have graded linear and now You have print emulation,
means that Your colorist has done lin-to-log conversion,
and that he had placed KODAK 2383 (not 2183) 3D LUT.
It is normal that this pictures looks different.

But I see two problems here:

1.
You have graded linear, and You have some color-quality degradation in
lin-to-log process.
2a,
do You mean that You have blacks at level of 0 and some whites at level of 1023 ?
If that is the case, than Your grade is not correct.

2b,
or You mean that You have exported DPX using 10bit code values ?
Even than be warned that black is not 0, but 95,
and white is not at 1023.

Please give some more informations.
Which luts are you using ?
Arri, RSR, Kodak ?
What are Your displays ?
 
...also be aware that any time you give a colorist a LINEAR .dpx file you usually confuse the hell out of them.

So your options for greatest success are:

1. give them a normal LOGARITHMIC .dpx file (95-685 range)
or
2. give them uncompressed linear 16-bit SGI or TIF files (eg full range 0-65535).

Since you're doing a feature, #1 would save some time and disk space so try that first.

Don't worry too much about setting up your own viewing setup (monitor, LUTs, etc) perfectly - overall brightness / color balance can be fixed easily over there. You often make things worse if you try to do a fancy color managed workflow of your own.

The trick is to not clip anything and get them something which consistently looks great on your setup. Then they can do the appropriate adjustments in a darkened room.

Sometimes you'd be surprised how little are needed. I used an un-calibrated $500 Dell 24" monitor for a recent title sequence I art directed and they only adjusted color-correction on a single shot (because I told them to). This was a colorful, detailed animation for a big film (over $50 million box office).

Bruce Allen
www.boacinema.com
 
Hi Rauf,

If I understood you correctly: inside Color, using redspace you are in a video color space. The result of your CC is what you what to be back on film, so it is kind of your "print".
I don't see the benefit to render out linear files, but would instead render exactly what you see, the redspace into either 10 bit dpx or 16bit tif/exr (I think 10bit dpx would be the best way and enough quality wise).
The lustre colorist/operator should then basicaly do a "video2log" conversion, then view it throuhg a print lut and correct to match your intention. It should be a fairly common process, like do a film out from a video tape (like a 10bit hdcam-sr tape).

My bad if I confused you more than I helped.

Good luck,
antoine.
 
Hi I used the range from 0-1023 because red recommended this at their white paper, I graded on a calibrated monitor EIZO 24" HD, it was great.
right now I'm at Moscow to do the film print, we are using lustre and Kodak 2383 stcks, so we are using the kodak 2383 lut for this, and for the display we are using Barco dlp projector, the viewing here through projector looks exactly like the 35 mm print, and we are using arrilaser.
but as I told you guys the image looks compressed so much from the range 100 to 0 of my version of color correction, and the color is mapped correctly, so my major problem here that luminance or let's say: the contrast is much more than what I made, so I lost details at the range 0-100 and it turned to black on the 35 mm print.
is this happening because of the lin to log conversion، that has clipped the range between 0 to 85 from my original DPX, and clipped from 1023 to 685 range?
the colorist here is always afraid to touch the lift and let me see what happens, or try to lower the contrast.
maybe if I could lift up the levels, then put the gain down, and make the contrast correction, crush a little bit of shadow that will be great for me, because the color is great really.
I'll upload you an example of what I have here.
 
here is the difference, the correct gamma is what I want (REEL01_0001693_Correct-gamma.jpg).
and the other is what I get (REEL01_0001693.jpg).
this film is all shot at night situation, and it's very delicate in case of crushing the gamma down.
I've made this conversion in shake Lin-->Log, this is my settings (Settings-in-Shake.jpg)
how could I tell the settings to Lustre colorist (any special attributes in Lustre)?
can any one made a 3d lut for this settings, based on kodak 2383 lut?
 
The hole point of making a 3D lut is to be made at the grading facility.
It involves a profiling of a specific device with specific calibration.
So answer is no, You can't use anyone elses 3Dlut.

What You have done in shake is 1D lut conversion.
Ask Your colorist to go to
IMAGE-INPUT LUT -CUSTOM-....
Than he has to choose some custom 1D lin to log lut which he will make/edit,
which he will use for Your new proper conversion.
However, he needs to know to do that.

Are You at Cinelab ?
If it is so, than You should tell them to call Cedric Lejeune, from Workflowers,
he had setup their system, and he can help them on this issue.
 
Hi Rauf,

I am not sure to follow you: you graded in Color in redspace and rendered out dpx full range in linear space.
For what did you use shake for?

Thanks,
antoine.
Click to expand...

I used it now to do a test for lin-->log conversion, and the photo is what settings I used.
I could mange to use color to convert the DPX sequence to Film Log 95-685, and it was great.
Is this conversion is going to solve my problem?
 
Rauf, my bad it was obvisous.

If you are happy with what you see in shake with the settings of your lin2log tool, then you may send this print screen to the colorist and they should manage to apply the same lin2log in their Lustre. But they would still need to apply the inverse of the gamma of the positive stock so when it is print back to film it will look exactly like your grad (well in acceptable boundry).
Because you graded without any print calibration lut, I don't think there is an easy conversion that you can do that will solve it, the colorist will allways have to adapt the video space to the film space.

Good luck,
antoine.
 
As I understand Rauf, you tried to prepare the material for the film out in Color in order to gain costly grading hours in lustre... I can say that, unfortunately it doesn't work like that...

Your best shot is to grade in a REC709 monitor, by keeping your blacks and whites not clipped, unfortunately in linear (following "the poor man's" DI method, not high quality Log from start to end), with enough headroom to be re graded in lustre... of coarse use linear images with no conversion LIN>Log, let lustre to do it...

Sorry but you have to pay extra in lustre to do your job...

The dark movies are the most difficult to be accurate in the film out...

A 3Dlut is always related to user_monitor>film_recorder>negative_emulsion>developing_lab>positive_stock so none can help you on that... Even if I wanted to help you, you should print your movie in our film recorder to be accurate... If that was the case, then you would be able to do a high quality DI, LOG all the way, in your facility and the zero copy would be perfect...

Only remember to use Color in the Linear always because there is a bug there... Log in Color is problematic, we using it in "linear" even if we have a Log workflow... so shake is a better chance...
 
Bruce Allen said:
...also be aware that any time you give a colorist a LINEAR .dpx file you usually confuse the hell out of them.


Bruce Allen
www.boacinema.com
Click to expand...

Not every colorist is such a dufus. Believe it or not, there are actually some colorists, that may even know how to deal with it:)
 
A big thanks to people who helped.
and good work gareme on the new update.
 
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