To use Cineon files, import them then apply the Cineon Color Converter to them. This will convert the 10-bit log data to 8-bit linear, and you have some control over the LUT used (ref. black, ref. white, gamma, etc.). At this point, you can apply any operator to the image. For export, you can save out as Cineon again with a LUT to convert the linear composite to log, or you can use any other format. Keep in mind that all formats except Cineon will save out as 8-bit since this is what combustion uses internally, with Cineon you save 10 bit by using a LUT to convert the depth.
Hope that helps,
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Greg Niles
combustion Product Specialist
Discreet