BackdoorArts
Senior Member
You also have to take into effect DX which gives you a longer effective focal length. I have found that VR lenses for the most part take care of the difference.
There is no DX crop factor/effective focal length adjustment with this rule. For example, say you have an 85mm full frame lens. If you have to shoot at a minimum of 1/85 sec (w/o VR) on an FX camera to prevent movement then the entire frame, from the center to outer edges, is covered. Had you been shooting the same camera in DX mode the rules would not have changed.