I played around last night taking a spectra of the centre of M8. It is quite interesting.
I have my LISA spectrograph on my VC200L. This is guided on the slit. On the same mount I have an ST10XME on my 127mm APO scope so can image at the same time through it. This is isually used just to find the correct star to align on the spectrograph slit but I decided to take a quick and dirty HaRGB image whilst the spectrum was being taken.
The first image is just 3x5 mins Ha with 3x1min through BVR photometry filters. The B is a bit out of focus as I didn't want to touch the scope whilst I was taking the spectra. There is a bit of blooming but it gives the idea.
The second image is from the guider in the spectrograph. It demonstrated where the slit is.
The 3rd is of the spectra, cosmic ray hits and all.
The 4th is a commented spectra.
It shows nicely the emission only property of the nebula.