POV-Ray can simulate focal depth-of-field by shooting a number of sample rays from jittered points within each pixel and averaging the results.
Aperture
:
To
turn on focal blur, you must specify the aperture keyword followed
by a float value which determines the depth of the sharpness zone. Large
apertures give a lot of blurring, while narrow apertures will give a wide
zone of sharpness. Note that, while this behaves as a real camera does,
the values for aperture are purely arbitrary and are not related to f-stops.