Updated : 2021
The unsharp mask filter in Affinity Photo can be found in the sharpen category in the Affinity Photo's filters menu. The tool create super sharp and intense images in seconds as well as subtle changes to any image in Affinity Photo. It is a destructive filter effect
Filters menu in Affinity Photo
Sharpen menu
Unsharp Mask filterSet radius
Set factor
Set threshold
Apply
The unsharp mask can also be used in channels, it can be used with layers and blending modes, it can be used with selections of any shape, it can be used in combo with other effects and repeated by using the unsharp mask with the Affinity Photo macro feature. It can be used channels to apply the unsharp mask with the red channel and not the green channel. You can use it with pattern layers as well as with the pattern layer source design.