i never do every pass.

a lot of times i do an AO pass for some tweaking. and if i have  something glowing in the scene then i also do a seperate pass so that i can then do a glow effect.

sometimes i also do an ''light matte''. like i was talking about. that way i have 100% control what color the lights is. it becomes very practical when you do color correction and you want fantasy colors.

if i do an AO pass then i turn of shadows and turn on shadow only. if you only have IBL turned on and shadow only set then you get an AO pass.

i think a ''reflection pass'' would be very good. is there any python script for that? so that we could render out only reflections?