I am reasonably computer literate otherwise I wouldn't have even tried to do colour matching myself. I am a botanical artist and since switching to Affinity Photo from Photoshop I have real problems with the unsharp mask. I scan my images in at quite a high resolution to get all the detail and therefore my image sizes can be quite large. I don't want to reduce them for printing for fear of losing the detail. Presently one of my images is 12 x 15cm at 800dpi. As previously mentioned in other posts, as soon as I merge the unsharp mask, it disappears. I have just done it at 100%, and had to increase the radius to 2.9 and factor to 3.248 before I got any sharpening at all. It is getting so frustrating, but as a pensioner I can't afford Photoshop anymore. With everything else so far I am very happy with Affinity - I am learning.
Unfortunately I am a perfectionist and it has to be just right.