|
The IF and DX parts of the lens name relate to two totally different things , DX are the letters given to a lens designed for use on crop sensor bodys like your D7000 , lenses designed for use on full frame bodys are given the letters FX .The IF part of the lens stands for internal focus which means that the lens does not extend when you turn the focus ring because all the movement is done inside the lens body , a non IF lens will extend when you focus .
Mark
|