Here is a link to all kinds of info (and some you might not know about ) concerning render layers . Should help alot of you folks just getting into maya that find working and rendering with layers hard to understand.
This link also address's the problem Lokjutus had with batch rendering.
https://www.3dtutorialzone.com/tutorial?id=88
Hi THX1138, that tutorial is only valid for older versions of Maya (2010 or 2009, can't remember) and down to 7. Parts of the tutorial are wrong as well. Occlusion is NOT supposed to multiply over-top an image. See: https://simplymaya.com/forum/showthread.php?t=37042
We also have a full tutorial here that covers render passes, and basic compositing: https://simplymaya.com/autodesk-maya-...ke/?tut_id=202
Imagination is more important than knowledge.