I recently received an email from Sean McHugh, author of cambridgeincolour.com, notifying me of new portrait-lighting sections on his site. These new sections feature nifty 3D renderings, and excellent explanations. If you've never visited this site and are, like me, looking for clear explanations of photographic technology, this is something you have to check out. Below I've listed links to the aforementioned sections and to the site home page. Hope you enjoy it.
I'll post another section on reverse engineering this coming week.