This is a 15 hour exposure of Eta Carinae taken from about 15 km of Melbourne CBD.
The camera used is a first generation SBIG ST-8300 Mono 1x1 binning using Baader Narrowband Filters running at -15C.
12 X 25 min in S2
13 X 25 min in Ha
13 X 25 min in OIII
Vixen R200SS – (f4 200mm Newtonian)
I pushed the exposures to 25 min to see what would happen. I think I am reaching the limits of the camera. The Ha exposures were bloated significantly around brighter stars. Unfortunately, the short well depth of the 8300 chip showed it’s head on this occasion in the Ha data. I believe that the O3 and S2 channels could still go a little further. Perhaps up to 30 min before significant star bloat.
Image processing - CCDStack was used to calibrate, register, normalise, perform data rejection, and stack the images. Final processing was a combination of Photoshop and ImagesPlus. Image processing is definitely an area I still have to work on, resisting that urge to really push it too far.
The mount is an Astro-Physics 900. This has been the one item that has transformed the hobby for me. It's the only thing that just works. I never worry about it.
