It's well known that all other settings being the same, larger sensor translates into a shallower DOF.

However, for the same number of pixels, doubling linear size of the sensor size would quadruple size of the pixels, and therefore increase ISO by 2 stops. This allows reduction of aperture by 2 stops on the larger camera, while maintaining the same ISO.

It's also well known that all other things being equal smaller aperture translates into a deeper DOF.

Thus the question: if you linearly increase sensor size 2x and reduce aperture by 2 stops would you get a deeper DOF (as lower aperture would suggest) or a shallower DOF (as the larger sensor would suggest)?

  • This is effectively an exact duplicate, although the scenario isn't exactly the same. In your example, it works out the be, theoretically, almost exactly equivalent — they cancel out. – mattdm Mar 17 '15 at 2:22