if you're talking about compiling then...
there are a number of tweaks to RAD you can do to affect the lighting, like extra, bounce, etc. the best and easyest way to use them and find out all the options you have (including the options for CSG, BSP, and VIS) is by using this batch compiler:
http://countermap.counter-strike.net/Nemesis/index.php?p=3 .
this batch compiler gives you a list of ALL the options you have when compiling along with a description of what each does. then, instead of typing in the commands, you just need to click on the ones you want. its simple.
another benefit to using the batch compiler is that you can close hammer when you compile. that frees up extra memory for compiling so it doesnt take so long.
after you download the batch compiler, follow the tutorial at that site for setting it up. once you use it you'll never go back to the old way... i guarantee it.