paulkosmala wrote:Few are technically knowledgable enough to give a coherent reply.
I was unaware prores film mode was not rbg...
The full name of
ProRes (HQ) is
ProRes 422 (HQ) which implies Y'CbCr coding.
balazer wrote:The low contrast appearance of Film mode footage is a completely separate issue from the low saturation: it's a consequence of taking the camera's log-transfer large dynamic range and displaying it in some smaller dynamic range display-referenced standard like rec.709 or sRGB without properly mapping the levels.
Log output from most other cameras (Alexa, F65, C300 etc.) is also wide gamut, and therefore appears desaturated prior to colour matrixing. This means it should not be expected to use the full range of the Cb and Cr channels. This could be regarded as "wasting" bits, but it could also be considered as a contributing factor to compression efficiency.
balazer wrote:Is there an official specification of the Blackmagic cameras' colorimetry for ProRes output when Film mode is selected? Specifically, I mean the RGB primary chromaticities…
To be pedantic about the original question, a camera does not have RGB primary chromaticities. It has overlapping spectral responses in the RGB photosites. The camera's colour matrix converts this into something approximating RGB primaries.
I believe that the details of this process are not publicly published at this time.