Thanks guys.
Ken, the calibration is from a home brew Python script I wrote, hence the somewhat dodgy results. Basically dividing the raw spectra by the reference, and then applying a smoothing algorithm on the resulting curve to eliminate the peaks. Obviously the results are not quite right.
I'm on Linux, and have tried using VSpec under an emulator but it is somewhat 'crashy' and not every feature works. I've since found a nice tool called splat-vo (
http://star-www.dur.ac.uk/~pdraper/splat/splat-vo/) that allows me to do the calibration process pretty much as described in your book (which has been a fantastic help by the way, thank you). I still need my script to do the wavelength calibration, but I think I have the maths correct for that. Here's the result of using doing the camera response through splat-vo, which gives a better result.
Still have a few things to iron out, but getting there. Now just need this cloud to stay away for 10 minutes so I can have a crack at Nova Del.
Malc