Crop factor and distortion

theregsy

Senior Member
I think I am right in my thinking here but confirmation would be good.
If I put a normal 50mm lens on my D2x with its crop factor I get the viewing angle of a 75mm lens, which is good. Now a lot of people recommend a lens of this type of zoom for Portrait work (70mm or so) now the crux of my question although my view looks like a 75mm I am still going to get the distortion of a 50mm lens in any portrait shots I take? as the distortion is inherent in the fact that it is a 50mm lens no matter what the crop factor might do to the viewing angle?
Any comments welcome (before my head melts! LOL)
Thanks
Mark
 

Joseph Bautsch

New member
Mark, you will actually get less distortion with a 50mm FX lens. Most lenses have their distortion in the outside edges of the glass. A DX camera will use more of the center of the glass than the outside. It's often called the "sweet spot" of the glass. However I would not think you will have much problem with distortion in any case. The Nikon 50mm prime is one of the sharpest lenses made by Nikon and has little distortion at the edges even on a FX body.
 

theregsy

Senior Member
Joseph, thanks for that reply. :)
I thought I had a good handle on crop and its effects on lenses but I just re-read a bit on portrait photography where they were on about using a 70-80mm lens for les distortion and it started me thinking (maybe I should stop either reading or thinking! LOL).
Thanks for clearing that up :)
 

Joseph Bautsch

New member
I think what they are referring to in portrait work is barrel distortion. That is more prevalent in the wider angle lenses and less of a problem in a telephoto. That's why it is recommended that a 70-80mm telephoto be used for portrait work. It also depends a great deal on the quality of the lens as to the amount of distortion present. The 50mm Nikkor has little or no distortion especially when used on a DX body with the telephoto effect. That is why you hear so many photographers recommend the 50mm as a good portrait lens.
 
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