Finally got to see some stars tonight.
I spent some time doing other stuff (tweaking polar alignment, etc), but eventually managed to capture these spectra of Eta Carinae as an experiment.
Each spectra is a stack of 4 images. The blue profile is an exposure of 4.841s, the magenta is 8.158s exposure. I wanted to get more at about 2s, etc but the clouds noticed me... The aim of the experiement was to find how much exposure I can us before the DMK ceases to be linear. This shows 8s is too long. Next opportunity I'll do a 4s cw 2s just to confirm 4s will be OK... it looks like it might be
. Good agreement between the two spectra, except for Ha. Both profiles are corrected for camera response and normalised.
Al.