Cannot choose ProPhotoRGB as output profile

I know this list, and so I recently used the one with “large” and the latest version: “RTv4_Large”

I’m guessing you want to save a large-bitdepth TIFF for import in another program… ?? If so, RT_Large will work just fine for your intent.

Correct, I will use 16 bit uncompressed TIFFs as my digital negative (result of a focus stack), and for this I prefer industry standard profiles, even if they are copyrighted.

Now I see that I can “install” it on Mac OS for RT by just copy it to /Library/ColorSync/Profiles/Displays
It is not a good choice to use this path, because Mac OS saves display profiles there, and never output profiles for images. It would be preferable to use (~)/Library/Application Support/ColorSync/profiles directly.

Questions remain:

  1. I wonder that RT uses ProPhoto as working space but by default does not support it as output by default?
  2. Wouldn’t it be better to provide ProPhoto as default output for 16 bit TIFFs since no additional conversion is needed from working space?