Unfortunately, “sharpness” does not have a standard definition. It seems to be a combination of acutance, resolution, and perhaps micro-contrast. When you mix all that with focus-stacking, as I do, then it really gets difficult to sort out. I like the idea of the PC-E 19mm, enough to purchase it, but with close-up focus-stacking with this lens I find that I depend on a certain base “sharpness,” micro-contrast, acutance – whatever we want to call it. With the PC-E 19mm, when I looked past my in-focus areas, I found that the base-sharpness was just a little more blurry that what I want to see. It messes (IMO) with the rest of what is in sharp focus or in bokeh... lessening the overall effect I am trying to achieve.