Very nicely made, I had no idea all this exphotonmap stuff was actually functional!
I've gone through the whole document and only found two spots where things are a bit unclear to me:
It's best to forget the infinite light (use a blank environment) or enclose your scene in this case.
In this sentence in the "Tuning it" section, I'm not sure what to do with the infinite light. When you write blank, do you mean it should be white or nonexistent?
The second part is the final gathering section (
http://www.luxrender.net/wiki/index.php ... ther_Angle). I found your text to be only partly comprehensible so I have tried to rewrite it in different words. However, the questions is if what I wrote is correct. It would probably be good if LordCrc had a look at it.