My Fuji camera with Super CCD may be better for this task:-
http://www.dpreview.com/news/0301/03012202fujisupe rccdsr.asp
I have found that my Fuji S5 seems to be surprisingly sensitive to UV. I am going to give Fuji a call tomorrow and see if the camera can see into the infraRed range too.
There is a special version of the Fuji S5, designed for forensic use, FinePix IS Pro See here:- http://www.dpreview.com/news/0707/07071304fujifilm ispro.asp
which would be hand for some kinds of astro and nature photography.
I will give Nikon a call too to see if I can do something similar with my D200.
Stephen Walters
G7VFY
07956-544202