>>2841169All lens except todays few superlenses get soft wide open. Mines peak performance is at f/5.6. Also that example shot is worthless because it is at such an angle it is near impossible to get most of it sharp. What you see there as "not sharp" is actually the bokeh.
BTW have you tried it on a macro extender? mine performs quite well. Excuse the bad shot, I was just quickly testing it around the backyard.
