This lens is really an excellent fast normal lens for crop sensor cameras. Reports of sample variations do
persist, but if you get a good copy - it is very hard to beat this lens at any price point. Even the vaulted Nikon
28mm
f1.4 (No longer in production, and close to $3000 for a good used copy) is not as sharp in the middle
as the
Sigma. Edge sharpness is another matter. Wide open it is fair..stopped down it will reach good to
very good. My copy has
an odd left edge poor sharpness while being used close to wide open (propably a
de-centered element). However,
being aware of this I can crop it or
frame in camera taking into account the
less than 5% of the frame that is
effected. Another quirk of this lens is the occasional tendency of the lens
to not mount completely...causing
a flashing top LCD. A quick remount solves this. Even so, I highly
recommend this lens. I rate the Sigma
30mm f1.4 a 9 out of 10 for build quality, and IQ.
