RED Log

It's Friday, the traditional time where we at ProLost sit back with a glass of tawny port and reverse-engineer camera transfer functions. Join us, won't you? Today's subject, RED Log.

RED Log is one of the options available in RED Alert (or the at-your-own-risk RED Cine). It's a logarithmic transfer function that appears to be designed to map the camera's linear-light image to a DI-friendly tonal range.

Like Panalog, the RED Log transfer function can be matched using the Cineon log/lin tools available in common compositing applications.

Here are the correct settings in After Effects (set to display pixel values in decimal):

In Shake:

And in Nuke:

Comments

[Marcus]

Stu
Thanks For yet more useful info !
any idea how these settings would work in Apples Color program, I'm puzzled how I can use REDLOG in Color?

[jaan]

it's like "Revenge of eLin".

[yohance]

Hey Stu


I'm a scratch colorist. I use a rec 709 lut when working in scratch. I have some vfx shots to hand off to some after effects guys. I'm sending them Redlog dpx files. Your red log transfer function sounds like the way to go however this method will bring the fx artist only half way to the correct preview. It takes them from a Red log to what I call Red Lin. Do you have a transfer function that will then take them to from Red lin to Rec709?

[Daniel]

Stu, mind if I ask you why the different gamma's depending on the app? Is that taking into account different color spaces? Isn't linear the same everywhere?

[Stu]

Daniel, the different apps (annoyingly) use different calibrations on the gamma control. These settings all produce the same results.

[san]

i leave gamma as it is just do both Log to in & lin to log in end

[Simon]

Sorry if I'm missing the point, if you get footage from Red Alert exported as Red Log, are they good to go or do you need to do this conversion as well ?
Or are these just illustrations of how Red Alert converts to Red log.
I'm getting confused as your illustrations are set for log to lin.
Thanks !

[Stu]

These settings would be used to convert REDlog to linear-light and vise versa.

[Stephan]

hmmm... your after effects settings seem to make everything black upon RED to Lin.... am I doing something wrong?