once i start working up a kasumi edge, i find it difficult to see refinement under magnification. synthetic is easy to watch the previous stones scratches be removed, but with jnats/nagura i eventually reach a 'limit' in what i can see. i definitely see the kasumi get tighter and cleaner but eventually i reach a limit on what i can 'see'. even after using a number of finishing stones/nagura. purhaps the edge gets softer/brighter but i cant tell for sure any more. and i dont know if the next nagura is actually improving the edge, or walking it back.

besides the obvious - shaving - is there any other way to tell if an edge is being improved?