Sigma 18-250 OS Review
My wife uses this lens on her D200, I happen to read a review in one of the digital photo magazines that compared this lens, to the Tamron 18-270 VC and Nikon 18-200 VR equivalent. They seem to think the Sigma was the overall winner in that price range. I have briefly tested the original Nikon 18-200 VR lens, and I would have to agree that in this case the Sigma is the better over all lens. The Sigma has a wider zoom range and can be found in the US for about $300 dollars less. I think the lens is very good in the 18-70mm range. It compares very closely to other consumer DX lenses that stop at 70mm. The aperture starts out at f3.5 at 18mm, around f5 at 70mm . The long end from 200 to 250mm is where it is the softest, but stopped down to f8 or smaller it isn’t too bad.
The top shot above was just resize for the web, with no editing. The second set are both a 100% crop of the birds head from the first photo. The only difference in two side by side images, is that one has a little sharpening added. It was taken at 250mm, f8 at 1/750 sec with OS off, ISO 200. Yes there is some loss in detail at 100% crop compared say to a17-55 f2.8, but this lens is one third the cost. The only other lens worth mentioning in that price range would be the Nikon 70-300 f4.5-5.6G. It would be sharper at the long end, but you miss out on the 18-70mm range, and would need a second lens to get there.
Given its compact size, HSM and OS, make this lens very versatile for walking around or travel. My wife hates to change lenses, which makes this a good one stop solution for her.