ok so im looking at these two lens' and was originally thinking about getting both....buuuut....there almost the same focal length, and both very sharp at f/2.8 and lower, so why get both? could the 60mm macro be used in place of the 50mm in pretty much any situation? if so then y get both? the 50mm im looking at is Canon's 50mm f/1.4, so i know there is a difference between f/1.4 and f/2.8, but from what ive read the 50mm doesnt really attain superb sharpness until f/2.8 and the macro has superb sharpness at f/2.8, so basically why get both versus just the macro? thanks!