We’ve delivered 2 minutes of dpx files, straight from Blender sequencer, to the film lab Cineco here in Amsterdam. The first digital projection in their grading room looked brilliant! (Gigantic new Barco projector). It’s now being moved to the Arri Laser to make 35 mm film, anamorphic 2.35:1 aspect. In a few days we’ll get a screening. Exciting!
Thanks to Blender’s linear workflow now, we should be able to give them perfect linear DPX files, for them to convert to wonderful film colors. However, it’s never as simple as it seems!
Here’s how we did it now:
– Files rendered in 2048 wide, 872 pixels high. This matches the standard for film, so no scaling is needed.
– DPX files (3 x 16 bits color) saved as linear – default in Blender with linear workflow enabled – but with a gamma 2.2 applied (code not committed yet). That is the thing that confuses me most… but according the Arri operator at Cineco it is “the standard”. Their LUT conversion (lookup table) assumes this to go to film color.
– At first we made the mistake to test DPX files saved from 3×8 bits sources, but these are not linear! So DPX ended up in the color space of the 3×8 bits graphics.
I also had to fix the header in DPX files to not denote a gamma anymore, for some reason that gamma value doesn’t denote what the data is, but what the files should be corrected for in displays (confusing!).
People with DPX and film pipeline experience are welcome to feedback here. A dpx file and the corresponding jpg can be downloaded below.
(BTW: the graphic looks a bit dark, but was in the screening room totally brilliant! Dark tones survive much better in projection than on screens. Do we have to make a special graded version for LCD and TVs)?