I plonked the lumbering 20” light bucket where I thought the middle of a nebula was. After processing 15 exposures of 30 seconds I could see a swirl on the right hand side of my screen. Only after seeing that my flats weren’t up to the job and retaking them using diffused moonlight, I just revealed some very faint, large structure, covering the whole frame. Some of the patches may still be due to optical differences but I have missed the main other structured part of this nebula (to the lower right) and the nebulosity in this part is very dim. It just shows that this nebula is far too big to capture with the ~40 arc minute sized field of the Canon on a 2.4 metre focal length scope and I should check exactly what I’m pointing at in future (difficult at the time). Plus it is far too red for much of its light to penetrate the cyan filter glued on top of the camera’s sensor.
Tuesday, 25 January 2011
IC 1871, well... part of IC 1871.
I plonked the lumbering 20” light bucket where I thought the middle of a nebula was. After processing 15 exposures of 30 seconds I could see a swirl on the right hand side of my screen. Only after seeing that my flats weren’t up to the job and retaking them using diffused moonlight, I just revealed some very faint, large structure, covering the whole frame. Some of the patches may still be due to optical differences but I have missed the main other structured part of this nebula (to the lower right) and the nebulosity in this part is very dim. It just shows that this nebula is far too big to capture with the ~40 arc minute sized field of the Canon on a 2.4 metre focal length scope and I should check exactly what I’m pointing at in future (difficult at the time). Plus it is far too red for much of its light to penetrate the cyan filter glued on top of the camera’s sensor.
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