Difference in Unsharp Mask between iPad and Mac

[daduran]

Is there a difference between the Unsharp Mask on the iPad and Mac? If I am doing it correctly on the iPad then it just means the Unsharp Mask Dialogue boxes are different between the Mac version and the iPad version. The Factor adjustment on the Mac has a value between 0 - 4, and the iPad has a Factor adjustment value between 0% - 100%. If that was intended, then am I correct to assume that 1 = 25%, 2 = 50%, 3 = 75%, and 4 = 100%? Visually they do not seem to align at all with these value comparisons. Am I in the wrong location to perform the Unsharp Mask correctly on the iPad?

 

[James Ritson]

Hi Darin, the Unsharp Mask implementation on iPad is quite different compared to desktop (it's hardware accelerated using Metal compute). I'm not entirely sure why the developers changed the factor from value to percentage scaling, but I can tell you that the equivalents are:

 

Factor 1: 20%

Factor 2: 40%

Factor 3: 60%

Factor 4: 80%

 

Be aware that whilst these figures will get you in the ballpark for similar sharpening, the Metal compute implementation appears to be slightly tamer, so be prepared to use a slightly higher Factor value (or indeed Radius). Hope that helps.

[daduran]

Thanks! That is very helpful. I am working on images on both the Mac and iPad (while learning how to use the apps - new to Affinity Photo).