looks for capture one, darktable and rawtherapee

capture one can't load a .cube, so a look made in luttie couldn't go there. now it can, along with the free raw editors.

• –capture one (beta): choose capture one in the lut export, or turn any .cube into one with the lut converter. you get a zip with a style and the colour profile it applies. it's marked beta because we haven't opened it in capture one ourselves yet, and on raw files colours are close rather than exact.
• –darktable and rawtherapee: the lut converter writes a haldclut .png, the format darktable's lut 3d module and rawtherapee's film simulation load.
• –affinity photo, darktable and rawtherapee guides: each has its own page with the steps from its manual, and all three are in using luts in other apps.