difference between focal length and film width?

[shortcirkuit]

Hi guys

In corona, i always only play with the focal length, however there is also the FILM WIDTH - ive never touched that.  What is the difference?  Does anyone use it?  If so why?

[romullus]

If you don't need to match the photos taken with real world camera, then you don't have to worry about film width in a renderer, just leave it at default and you'll be fine. Film width defines the size of camera's sensor and affects such parameters as lens magnification and DOF.

[maru]

The difference is the same as between using a digital camera with an APS sensor, a 35 mm film camera, and a medium format 10x10 cm film camera. :)