[mst]

I just replaced my Sigma 30 f/1.4 (Art) lens with the Canon 35 f/2 IS. Does not matter how sharp a lens is, it is useless to me as long as it cannot focus relaibly.

What issues did you have?

I ask because I just finished the field tests with this lens. It showed severe backfocus on the D7000 (which works perfectly with other lenses), while AF was spot on with the D7100.

Kind of proves my theory that front-/backfocus is often an issue of a camera/lens combination, not just the lens or camera.

Apart from the backfocus on the D7000 (which was within the limits of in-camera AF micro adjustment) the lens did not show any AF issues during my tests...

-- Markus