For anyone using Photoshop, or similar, for matte painting work on projects that are using a DI workflow with calibrated LUTs it is possible to match the Photoshop output to the DI workflow.
Photoshop, and similar systems, use ICC profiles for colour management rather than industry standard LUTs.
But, it is possible to make ICC profiles from LUTs using Light Illusion’s SpaceMan ICC system, or the provided LUT Conversion service.
ICC profiles generated this way have been used on a number of recent feature films, including the last 2 Harry Potter films.
More info on the Light Illusion website: http://www.lightillusion.com/spaceman.htm
And I’m always happy to answer and calibration questions.