Originally Posted by
Polar01
The reply #9 by Jeremy is so, so wrong. Now Jeremy is a long distance sports shooter that is sports he shoots are those that you just can not get close to, ie: speed boat racing, jet skiing, motor cross, etc., so using a FF lens on a crop camera as he does means he can get that extra reach that he requires.
However what if you want wide, well if you were to follow his advice the best you could do would be the 14-24mm f2.8 which on a crop you give you equal to a 21-36mm. That is not that wide, however if you were to use a 10-24mm DX lens you would not be equal to a 15-36mm. I will tell you that there is a big difference between the field of view of 15mm compared to 21mm.
The lens is a tool to use, you need what you need, if that means a DX lens than so be it, so those that make statements like the one Jeremy did, well that works for them it does not work for me in some cases and it may not work for you.
If you were wondering I have the following 10-20mm Sigma DX, 16-85mm DX, 16-35mm FF, 50mm FF, 70-300mm FF, 80-400mm FF, and a 105mm FF with a D7000, and a D600 I got the tools that I needed at the time.
Cheers: Allan