09-29-2010, 02:27 PM
That's a difficult decision. Do you want a 70-200 because you actually want the field of view of a 105-300mm lens (you aim for more telephoto) or do you want to have the field of view of a 70-200mm lens on DX?
If you actually want a lens that performs similar to a 70-200mm lens on your D90, then you should consider the Sigma 50-150 f/2.8 HSM II.
If you look for even more telephoto than a 70-200 and think that f/4 is bright enough you could also take a look at the Sigma 100-300 f/4. It does not have stabilization, but offers even more tele for your D90. I think however that at 300mm you need to have a very very steady position to avoid blurring. You should aim to have shutter speeds of 1/500s or faster. The Sigma 100-300 was reviewed here on Photozone on the D200 and received a highly recommended rating.
Also beware of some 80-200 f/2.8. There are some designs that are push-pull based, meaning you do not turn a ring on the lens to zoom, but push the lens out and pull it back. I've heard that push-pull can be rather inconvenient when shooting upwards or downwards as the lens extends or retracts due to gravity. When the forces that hold the barrel in place are not strong enough carrying such a lens around is probably not very funny.
If you actually want a lens that performs similar to a 70-200mm lens on your D90, then you should consider the Sigma 50-150 f/2.8 HSM II.
If you look for even more telephoto than a 70-200 and think that f/4 is bright enough you could also take a look at the Sigma 100-300 f/4. It does not have stabilization, but offers even more tele for your D90. I think however that at 300mm you need to have a very very steady position to avoid blurring. You should aim to have shutter speeds of 1/500s or faster. The Sigma 100-300 was reviewed here on Photozone on the D200 and received a highly recommended rating.
Also beware of some 80-200 f/2.8. There are some designs that are push-pull based, meaning you do not turn a ring on the lens to zoom, but push the lens out and pull it back. I've heard that push-pull can be rather inconvenient when shooting upwards or downwards as the lens extends or retracts due to gravity. When the forces that hold the barrel in place are not strong enough carrying such a lens around is probably not very funny.