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-   -   SLOG3 False Color LUT (https://www.dvinfo.net/forum/sony-digital-cinema-camera-systems/538414-slog3-false-color-lut.html)

Joseph H. Moore December 1st, 2021 09:52 PM

SLOG3 False Color LUT
 
I'd like to share a false color LUT I made for monitoring SLOG3 while shooting.

My goal with this LUT is to display a properly transformed REC709 image that is both good for judging exposure AND pulling focus.

My problems with most other false color LUTs are:
1. They're designed for a REC709 image, so if you're shooting SLOG3, they're off.
2. The false color is overwhelming. Assigning every value to a color makes the image a confusing rainbow.

With this LUT, I only color a few key ranges:
Middle grey = green
Caucasian skin = peach
Nearly crushed shadows = blue
Nearly blown highlights = red

Because the majority of the image is a B&W image with proper contrast, I can keep the LUT up even while puling focus.

Posting link to the LUT here in case someone else might find it useful: https://drive.google.com/open?id=19T...m&usp=drive_fs

Doug Jensen December 2nd, 2021 09:11 AM

Re: SLOG3 False Color LUT
 
What are your actual IRE targets for each of those ranges?

For example, what do you consider "nearly blown highlights"? In other words, if I expose an image that has areas that are shown as red on the viewfinder and/or monitor, what will the actual level be of those areas on the scopes in Resolve when I look at my ungraded footage? And what is your actual target levels for middle gray and Caucasian skin? That is basic information that needs to be known.

Also, do you only shoot Caucasians? If not, how do you expose for non-whites?

Joseph H. Moore December 2nd, 2021 09:37 AM

Re: SLOG3 False Color LUT
 
Hey Doug,

The LUT starts with the proper technical transform for SLOG3 to REC709, so these values are POST color space transform:

Blue below 10
Green between 45 - 55
Peach between 55 - 75
Red above 90

The color coding is a smooth ramp, not a hard cut like most false color systems.

I expose for "non-whites" the same way I expose for everything...to taste. ;-) I wouldn't put always put AA skin in a certain range any more than I would always put caucasian skin in a certain place.

This is just a tool to help visualize the exposure range and ensure the scene is landing where you want, it's not proscriptive of where it should be.

Joseph H. Moore December 2nd, 2021 09:39 AM

Re: SLOG3 False Color LUT
 
1 Attachment(s)
Here's a grab for reference.

Doug Jensen December 3rd, 2021 08:33 AM

Re: SLOG3 False Color LUT
 
Quote:

Originally Posted by Joseph H. Moore (Post 1966531)
This is just a tool to help visualize the exposure range and ensure the scene is landing where you want, it's not proscriptive of where it should be.

Hi Joseph,

Thanks for the additional information about the LUT. I'm not a fan of false color myself, but I find it interesting to hear how other people use their cameras, judge exposure, etc. There are certainly many ways to skin the cat!


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