The simple answer is no. But it’s not a fair comparison for these reasons:
1. The Prores is in Rec. 709 color space, with a maximum bit depth of 10 bits per pixel
2. The Prores is chroma sampled at 4:2:2 and has two fixed preset options
3. The Prores/DNxHD file is downsampled to 1080p. You can’t shoot 2.5K in Prores.
If it were a fair fight, the difference would be minimal, in my experience. Only in better sensors like those found in DSLRs and medium format cameras do the RAW files far outweigh in-camera TIFFs or JPEGs. I could be wrong, though. Maybe BMCC has pulled off a miracle!
One important thing you should know is that RAW files have to be debayered as I mentioned earlier – this means that the RAW converter must have decent knowledge of how the sensor works to use the best algorithm for debayering. Right now, even though many apps support Cinema DNG, only Resolve really ‘knows’ the BMCC in and out.
As a simple exercise, I recommend downloading Raw Therapee, a small but really cool and powerful RAW converter. You could try grading the available DNG files to see if you can reproduce the look.
By the way, the BMCC manual is available now: https://www.blackmagicdesign.com/media/4720483/Cinema_Camera_Manual.pdf
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