A friend of mine is contemplating buying a K20D as his first digital slr, having been using film for some time. He has asked my advice about the Sigma 18-200 f3.5-6.3 lens. I have not got one, so if anyone has and can give some pointers as to image quality, then that would be great.

I have suggested the Pentax 50-200 f4-5.6 and the Sigma 17-70 f2.8-4.5 combination. Any comments on the 50-200 would also be helpful. I have the 17-70, so no help needed there.

Thanks,

Hmmm, just noticed on the Sigma site that the 18-200 is not available in Pentax fit......

David.