06-22-2017, 10:24 AM
Actually, Nikon DSLRs show the effective f-stop of "micro" lenses (even the plasticky 40/2.8), not only the max. available. Good thing for manual flashes, I think. This effect can be watched when focus at infinity, leave the aperture, then focuse at much closer - aperture number goes up. I'm not sure, if it's a full f-stop, but it is significant.