When using FX lenses on a DX camera, we use the crop factor to ensure we are choosing the best lens for the job. However, if a lens is labled DX, do we take the focal length at face value, or do we have to apply the crop factor as well?
#3. "RE: DX Lenses and Crop Factor" In response to Reply # 0
Welcome to Nikonians! The focal length of FX lenses and DX lenses are the same. DX lenses project a smaller image circle at the sensor plane than FX lenses. Since the sensor plane is in the same location on both FX and DX bodies as well as film bodies the "1.5 X crop factor" applies to All lenses when they are mounted on a DX body. Good Luck and Enjoy your Nikons!
#4. "RE: DX Lenses and Crop Factor" In response to Reply # 0
Rancho Cordova, US
I think in terms of a 35mm film camera (135 format) with a negative of 36mm x 24mm. When I think of lenses and focal lengths, I think in terms of what that lens will give me as an angle of view with respect to a 35mm film or FX digital camera: 24mm = 84 degrees 35mm = 62 degrees 50mm = 46°
In DX format: 24mm = 61° 35mm = 44° 50mm = 31°30'
But I'm not comfortable learning the angle of view for DX focal lengths, so I translate to FX angle of views with the 1.5x crop.
In FX, a normal lens is the 50mm lens with 46° angle of view in DX, a 35mm x 1.5 = 52.5mm whic is pretty close to 50mm and has an angle of view of 44° ... making it a "normal lens" for DX bodies.
Long story longer, yes, do the crop factor thing if you think in terms of film/FX lenses and are comfortable with it.