Sharpness of knives, hardness of wood, grain orientation, horsepower
and your technique all come into play. While taking off the high spots,
you could probably increase the depth of cut without any problems, but
when face jointing with the full width of your jointer, light cuts give
a better finish, IMO. A light cut allows better technique, too,
resulting in flat faces on thinner stock. I usually leave my depth of
cut between 1/32nd and 1/64th of an inch. Tom