On Sun, 06 Dec 1998 09:53:57 +0000, Tim Hague
>I find mine a bit soft generally from f/1.4 to f/4~5.6 when focused at
>medium to long distances. For close focusing (around 1m to 5m) it is
>very sharp wide open. I have no idea why this should be, but I've been
>rather disappointed with this lens.
Jes' goes to show that anomalous samples exist, I guess...;-)
The many I've checked pop up in contrast and are quite sharp
over most of the frame by f2 (I prefer not to use them wider...)
at infinity-focus, leaving the far edges a bit softer, and the
corners too soft for my taste (the f1.8 is better here...).
The edges/corners improve with stopping down as does the main
area of the frame, becoming excellent all over by f5.6 (though
for those people who don't mind a bit of quality fall-off at
the edges, f2 is fine, f2.8 even better, f4 really excellent...).
BTW, I find the 50mm f1.2 has the characteristics you describe,
with excellent mid-close distance performance at wide stops, but
with poor infinity performance wider than about f5.6 except
in the center...