108 of 109 people found the following review helpful
Good, but not great, all around lens.,
This review is from: Canon EF-S 17-85mm f/4-5.6 Image Stabilized USM SLR Lens for EOS Digital SLR's (Electronics)
From a pure image quality standpoint, this lens will not please the pixel peepers. On the wide end of the zoom, which I personally use more often than the telephoto end, this lens is not very sharp, and it suffers from fairly bad distortion. Worse than that, for me, are the chromatic abberations; this lens is quite prone to significant CA when shot at the wide end, which can look a lot worse than a little bit of distortion or softness. Given the price of this lens, one should expect a higher level of optical performance.
The maximum aperture of this lens is not very large, being f/4 on the wide end, and f/5.6 on the telephoto end. The image stabilization makes up for this some, as you can comfortably shoot at much slower shutter speeds than otherwise, but, let's be honest here; this lens is a poor performer if you want to shoot in low light with no tripod. The small aperture makes for a dark viewfinder, which can be a very big problem if you are trying to compose a picture in the dark (using a tripod).
Yet, I still gave this very imperfect lens four stars, and this is not without reason.
First of all, the focal length range is quite handy. It isn't a mega-zoom that does everything, however, it covers the most often used focal length ranges, and is an appropriate lens to use for the vast majority of situations. The little bit of extra zoom on the telephoto end is handy on occasion, and it's also worth noting that the lens sharpens up quite a bit when you zoom in some - it might be soft on the wide end, but zoomed in, it's quite good.
I have printed as large as 20x30" using this lens on a Digital Rebel, and have no qualms with the results. Yes, there are sharper lenses out there, but you are a lot more likely to see the difference in sharpness on your computer monitor than in a print.
This lens has ring USM, which enables it to focus very quietly, and very quickly, whereas the slightly cheaper (and F2.8) options from the 3rd parties have normal focusing motors that are slow and noisy by comparison.
If you want to use this lens indoors, you are best off getting a flash to go with it, such as a 430EX. The lens is usable in fantastic indoor lighting, or during the day, but won't give you good results in low light with no flash.
If you will be shooting in lower light situations (people in particular), Tamron and Sigma have some good options in the 17-50mm range with F2.8 apertures, and I would recommend those lenses over this one. If you'd prefer the extra telephoto range, the image stabilization so you can shoot with smaller aperture in poorer lighting situations for greater depth of field (instead of needing to shoot a landscape at f/4, for instance, without image stabilization, you could use f/11 on this lens, and get a sharp picture with better depth of field. This is even more useful in the close focus range - while this isn't a true macro lens, if you take closeup photos without a tripod, you will want to stop the lens down for greater depth of field, and the IS helps with that quite a bit.
Overall, I've been fairly pleased with the performance of this lens. If you like to worry about splitting hairs, and zooming all the way in on pictures on your computer, this lens is likely to dissapoint you. If, however, you are willing to sacrifice optical perfection to get a very well rounded, useful lens, then I'd recommend it, however, would also recommend that you consider the 3rd party options, as they are also great lenses, and do offer a somewhat better value.