I always enjoy reading papers that Valve and Crytek put out, so I wrote this paper about our experience implementing deferred lighting in our engine. It includes a few useful formulas. I hope you enjoy it:
http://www.leadwerks.com/ccount/click.php?id=50 Good read for with the morning coffee.
@ Tri, its a PDF, if the link doesn't open the reader try what i have to do. rightclick link saveas works for me anyway. don't know when or why but i can't view PDF's directly from links anymore so have had to resort to saving.
No FSAA when using deferred rendering can be a big disadvantage, depends on the overall outcome of this technique in terms of performance. The paper is not conclusive enough imho on the performance advantage of this technique.