I've seen the posts about the angle of view being the same for a 28mm lens on a 1.6 crop sensor as for a 50mm lens on a full frame. I understand it.

But what about the depth of field. Will that match too if the distance to the subject and aperture are the same?

  • The 28mm-->50mm conversion is fairly imprecise. 28mm on a 1.6x crop sensor translates to the same FoV as 44.8mm on FF. 31.25mm on a 1.6x crop sensor translates to 50mm on FF. The difference between 28mm and 31mm doesn't look that dramatic, but at f/2 and a 10' focus distance the difference in DoF (3' vs. 2.42') is about 7 inches! If the shooting distance is increased by just over 1 foot (to 11.07') with the 31mm lens to give the same FoV as the 28mm lens at 10', then the DoF is the same for both lenses.
    – Michael C
    Feb 4 '14 at 3:30

There are many apps and online DOF calculators, and the answer is: no, they're not the same. The full frame camera will have a considerably smaller depth of field with the same angle of view.

The formula for calculating the depth of field is quite complex, not at all a simple linear scale.

  • In the non-macro range, shooting with a 1.6x crop factor is like shooting with a 1.6x smaller aperture (larger number)... or pretty close to it anyway. Feb 4 '14 at 2:32

Not the answer you're looking for? Browse other questions tagged or ask your own question.