http://www.nikonchat.com/18-200mm-nikkor-vr-lens/
Bim Tamron 18-250mm or Sigma 200mm OS HSM-18?
d40 I have I would buy one of these two lenses. I know that the 18-200mm VR Nikkor is better, but I'm in budget. to compare the two, the tamron doesn't have optical image stabilizer, I go to Sigma or Tamron?
If you have shaky hands or throw often when is to keep shutter speeds above then you may want the optical image stabilizer to help you get sharper photos. Then difficult are 3 web links, these vendors have customer reviews, the last 2 links go directly to the customer reviews of Tamron and Sigma lenses on the site web for B & H Photo. Both are responsible for a great lens. I've used both and have worked well for me. Hope this helps. Marcos Marksablow.com
Nikon News