In all images below , jittered sampling with 64 samples per pixel was used. The field of view is set to 45 degrees. The image is an infinite chess board with size of a square set at 1 unit. We observe the effect of changing the aperture while keeping d0 fixed.
Depth of field is the range of distances from the camera which are in focus.
In all images below, d0 is set to 0.36. In all images below, the aperture diameter is set at 0.05 units so that almost everything is in focus.