color space

VFX footage input/output by Xuan Prada

This is a very quick and dirty explanation of how the footage and specially colour is managed in a VFX facility.

Shooting camera to Lab
The RAW material recorded on-set goes to the lab. In the lab it is converted to .dpx which is the standard film format. Sometimes the might use exr but it's not that common.
A lot of movies are still being filmed with film cameras, in those cases the lab will scan the negatives and convert them to .dpx to be used along the pipeline.

Shooting camera to Dailies
The RAW material recorded on-set goes to dailies. The cinematographer, DP, or DI applies a primary LUT or color grading to be used along the project.
Original scans with LUT applied are converted to low quality scans and .mov files are generated for distribution.

Dailies to Editorial
Editorial department receive the low quality scans (Quicktimes) with the LUT applied.
They use these files to make the initial cuts and bidding.

Editorial to VFX
VFX facilities receive the low quality scans (Quictimes) with LUT applied. They use these files for bidding.
Later on they will use them as reference for color grading.

Lab to VFX
Lab provides high quality scans to the VFX facility. This is pretty much RAW material and the LUT needs to be applied.
The VFX facility will have to apply the LUT's film to the work done by scratch by them.
When the VFX work is done, the VFX facility renders out exr files.

DI will do the final grading to match the Editorial Quicktimes.

VFX/DI to Editorial
High quality material produced by the VFX facility goes to Editorial to be inserted in the cuts.

The basic practical workflow would be.

  • Read raw scan data.
  • Read Quicktime scan data.
  • Dpx scans usually are in LOG color space.
  • Exr scans usually are in LIN color space.
  • Apply LUT and other color grading to the RAW scans to match the Quicktime scans.
  • Render out to Editorial using the same color space used for bringing in footage.
  • Render out Quicktimes using the same color space used for viewing. If wathcing for excample in sRGB you will have to bake the LUT.
  • Good Quicktime settings: Colorspace sRGB, Codec Avid Dnx HD, 23.98 frames, depth million of colors, RGB levels, no alpha, 1080p/23.976 Dnx HD 36 8bit