Originally posted by D1N0 I guess it was to hard to make AF work with such big chunks of glass.
The macro A 50/2.8 is not a big chunk of glass, and it also has a floating element.
My DFA 50/2.8 (optical the same as the FA and F, if I remember correctly), is much sharper than my A 50/2.8, but the DFA has a mechanical flaw, too flimsy with its double heliocoid (which makes it compact though) to keep the optics propper centrated, especially noticible in portret mode shots.
If I stumble over a FA or F 50/2.8, I will probably replace the DFA.