hello, I just got the n-90 and am looking for a good lens. I have a quantaray 100-300, but need a smaller lens. I don't know that I can afford a nikon lens, but if it's necessary-I'll try. So I'm wondering about the quality of Tamron, Sigma, Quantary or any others. I'd like to get a zoom from around 28 to 70 (or higher). I've seen some that are less expensive, but only have f4 to f5.6 or something similar. All of my previous cameras have had from 2.8 to 22. I don't know alot about lenses yet, so please let me know what you think. Thanks for your help.