Miss Nancy... these are just my settings for the fast test renders I was doing. I wasn't aiming for top quality. That's the only reason I was using IC = 0.   :O)

There's a lot of stuff that isn't covered in any useful detail in the manual. I was trying to find out about math node bias and gain functions last night, in order to understand what some of bb's shaders were doing. This is what the manual tells me:

Bias: adjusts the bias of Value_1 by Value_2.
Gain: adjusts the gain of Value_1 by Value_2.

Wow. That's really good to know!

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)