mrenters

This looks very promising and given the text file nature of the LUT, it can be programmatically generated based on measured density measurements. I've been printing 256 grey patches, measuring them with an I1 spectrophotometer and then calculating the resulting adjustment curve. Martin

Thanks for all the responses. It would be great if Affinity Photo added this feature. In the meantime, I've found that GIMP is able to do this, so I'll just use that for the time being. Martin

I'm trying to use Affinity Photo to make a curves adjustment layer for digital negatives that will be used in a traditional darkroom process. I need to be able to compensate for the response curves of the medium (e.g. photographic paper, cyanotype) I will be contact printing the negative to. I can calculate the curve but I can't find a way of telling Affinity Photo to make an adjustment curve where input value 5 maps to output value 20, input value 16 maps to output 32, etc. as is possible in Photoshop. I'd be happy to have a way to create a preset in the text file or something if that is possible as the curve would be the same for all images made into negatives and darkroom printed to the same medium. Any ideas? Martin