Originally posted by paperbag846 If you need sharp across the field just go with the DA 40. It's not the sharpest, but it's so sharp that I would argue it does not matter one bit.
Agreed. In fact, as the OP's original question was actually a bit broad-brush, just getting an M50 1.4 or 1.7 would be a good way of getting familiar with the kind of improvement one can expect in a better lens vs the f2, at very low cost.
How critical is sharpness anyway, once you get beyond a certain point....?
Any of the lenses mentioned are as sharp as you could need stopped down a bit; wide open, characteristics other than sharpness tend to be more important.