Unsharp mask for contrast

For Photoshop users ( and possibly others? ) I've found a more sublte way to alter image contrast is to use the Unsharpmask filter.  After-- Filter>Sharpen>Unsharpmask  set the Amount to around 15% ( not critical); Threshold to 0, then use the Radius slider ( pixels) to now adjust the contrast, say 100 Pixels to kick off with, then alter to suit your image.  Seems to be a finer controlled way of altering the Contrast than the usual Contrast adjustment provided.