Correct: currently, the best way for archive an ACES-based production is saving in OpenEXR sequence of frames compatible with the SMPTE ST2065-4 standard, that is roughly:
- OpenEXR file format;
- RGB or RGB+alpha, 16-bit/channel floating point codevalues
- No compression;
- Color encoding in ACES2065-1 color-space (thus no burning/rendering any Output Transforms);
- filling up ST2065-4 compulsory metadata fields in the OpenEXR header (e.g.
The reasons why this is the best encoding is future-proofing the color of the picture and making it independent of a particular display technology (like the Rec.709 monitor you have likely mastered the content today).
Use of a file-per-frame format (instead of an MXF-wrapped standard like, for example, ST2065-5) is preferred for archival due to several operational reasons.