Post Filter Size:  Supersamples pixels, i.e samples a pixel at pixel lever at different points to ascertain the final colour of that pixel, usefull for anti aliasing.
Increasing the size of this filter will increase the sampling rate but will also increase the render time!

If you'd said you'd misplaced your manual before I'd have posted this sooner!

Any other option you want to know about?

Hell IM me if you want and I'll scan the pages of the manual and send them to you if you want!!

Injustice will be avenged.
Cofiwch Dryweryn.