Is really radius in Unsharp Mask filter that large?

[ch22]

Hello

When enhancing a layer, one can check that identical results can be obtained by 

(i)             Adding a high-pass filter in linear light blend mode

(ii)            Or adding an unsharp mask filter (in normal blend mode) with a gain factor of 1 and a radius curiously threefold larger than the high-pass radius (for instance, 10 px for the high-pass filter and 30 px for the unsharp mask)

The same comparison performed with a well-known competitor software (somewhat more expensive) cannot lead to the same exact identity because of different definitions for the high-pass filter, but one can look for the best agreement when varying the gain and the radius in the unsharp mask. Then, the best radius is not exactly that of high-pass filter, but it remains close to it. I wonder whether the radius scale read in the unsharp mask dialog box of AP is not threefold too large. 

Obviously, this does not prevent the good operation of unsharp masking in AP