I'm confused.


If the most expensive lens out there are the fastest ones, then why do we need to stop them down in order to get the clearest, sharpest picture?


Dont we pay more for those low numbers??


I'm understanding, lately, that most lens are best around f8 .... give or take a couple of stops either way.


Somebody explain why we would pay nearly two thousand dollars for a low f stop lens when, if we get a better pic around f8, we couldnt be better off with a bottomed out f4?[:S]