Thanks Harald. I tried the compensate off to make it the same as USM and it looks good (to be able to compare) - just to check, you can only make the comparison, I assume, in Sharpen Edges mode? Also, there's no threshold like in USM - is it assuming 0? 1?
The Sharpen Edges mode only sharpens the edges and not the surface. I recommend to switch to Expert Mode or at least Selective Sharpen (Pro) mode. However, to simulate a USM filter in FocalBlade, please use the Sharpen mode with the Compensation check box deactivated.
The Treshold slider of USM produces salt'n'pepper noise in several cases, so I wouldn't recommend using it at all. Additionally it only keeps some areas unsharp instead of letting you sharpen them gradually. In FocalBlade you have the Edges and Surface tab sheets which give you more control than the Treshold slider and that without side-effects.
I also tried the screen/print to see the values of the sharpen sliders. The sliders do change - but only for the first button press when you change the mode. Try again inside the same mode pressing screen/print and nothing seems to change (either in the sharpness of the picture OR the sliders) - bug?!
Thanks for letting me know about this bug. It only affects the Sharpen Edges mode. I will fix that. The Sharpen Edges mode is only meant for special cases and for beginners. Please use the Expert or Selective Sharpen modes.
The same thing seems to happen with the Compensate as well. I changed to Sharpen Edges, chose max 400% to make sure I could see a difference, did the screen/print a couple of times to make sure it was doing nothing (:-(), then tried compensate a number of times. I could swear that, at 100% in every place on the image I looked at, nothing changed between clicks on/off. This could be another bug, perhaps? One difference was that in pressing screen/print, absolutely nothing happened (no cursor change to indicate processing), while the compensate click on/off did, very very quickly, have the cursor change to an hourglass; however, it was there for a much shorter time than for any actual change to the image.
If you deactivate the Compensate check box the Auto combo boxes will be deactivated automatically thus making the Print/Screen buttons useless. If you choose a setting from one of the Auto combo boxes, the Compensate check box will automatically be activated. The reson for this behaviour is that the Compensate function is an integral part of the auto mechanism. Without an activated Compensate check box it makes no sense for FocalBlade to do any automatical sharpening.
So this behaviour was added by design.