Quote Originally Posted by Gee Man
I was under the impression it would still perform (reasonably) well on a crop body?

For many photographers, the performance is more than adequate. The sharpness limitations of this lens would be difficult to notice at 8x10 and smaller print sizes, so it's correct to say that it will perform reasonably well.


It could be that your body is not able to achieve critical autofocus. Wide focal lengths show calibration errors more readily. Even if you miss focus just slightly it can make the lens look much worse than it actually is, so I would suggest checking that first. Filters, too, can reduce sharpness, especially on a wider lens. Make sure that any filters are removed.


It's also possible that your copy is even worse than most.


But even if you get a good copy and achieve critical focus, it will still not be quite as sharp as the 70-200 or or 17-50 and 18-50 lenses.