In the context of ASC-CDL, saturation is applied as:
luma = 0.2126*iR + 0.7152*iG + 0.0722*iB oR = luma + saturation*(iR-luma) oG = luma + saturation*(iG-luma) oB = luma + saturation*(iB-luma)
However, in the ARRI Look Files in the ALEXA Camera whitepaper they say:
Note: The ALEXA saturation parameter differs from the ASC CDL saturation.
But they don't specify in what way, and I can't find that information anywhere.
Does anybody know?