Summary: I cannot properly rate this lens since I only took 2 photos with it before returning it. I gave it one star because this lens cannot be used with a full-frame camera. If you intend to use this with a crop sensor, stop here and read another review.
Summary: Bought this lens as a replacement/upgrade for my Nikon 18-55 kit lens. Autofocus and speed are indeed better. The quality of the pictures are about the same. I guess I could sort of live with that. What I find unworkable though is the 'barrel creep' of this lens.
Sigma AF 18-200mm f/3.5-6.3 DC OS Zoom Lens for Nikon D40
Nataraj "eyeDance", Amazon
22 November 2008
Summary: UPDATE: This lens ceased functioning 14 months after I bought it. The local repair shop could not fix it, and said it needed to go back to Sigma. Minimum repair price was $125, and likely higher than $150. Plus shipping. I changed my rating from 4 stars to 1 star because of this.
Summary: This could be a good lens for the money. Except that it does not autofocus with some Nikon DSLR bodies, such as the Nikon D40X. I didn't see in the ad that it doesn't autofocus with some Nikon DSLRs, nor is this indicated in the information that came with the lens.
Summary: I was looking for an 18-200mm lens for my Nikon D50 SLR camera. Sigma is a recognizable trade name for lenses and the price of under $200 was appealing. The lens appeared to be what I wanted, however, the images showed significant "barrel" distortion and the expected maximum image magnification of...