I have one chart on reflectance. The opposite of absorption. I may be of some use.

http://en.wikipedia.org/wiki/Cannabi...29_cultivation
(itā??s 75% down the article)

Cannabis has a very unique reflectance and because of that police can use high tech cameras to detect cannabisā??s unique reflectance. They use it to find small outdoor grows via helicopters.

This unique reflectance makes me think it has a unique chlorophyll absorption and thats why i wouldn't trust the generalized info. Itā??s just such a unique plant in every aspect