M101, The Pinwheel Galaxy

I just had to have a go at LRGB imaging a galaxy, and try and include some H alpha in there as well. There are so many wonderful galxy pictures out there that I had to try as well. Unfortunately, it appears though I still have a lot to learn about it!!

The image below was put together from 35 x 5 min luminance exposures, 19 x 2 min R, G and B exposures binned 2×2, and 12 x 5 min H alpha exposures; R and Ha were blended together to form the red layer before creating the colour image.

I encountered a number of problems along the way. It appears that the Astronomik LRGB filters are not parfocal with the Baader Ha filter, for some reason I don’t quite understand, so I had to dump a lot of out-of-focus Ha frames. Getting the colour balance right wasn’t easy; the stars from the different filters were often different sizes – particularly the Ha – so there are some halo effects on the stars; and it also took me forever to do! And worst of all, there’s still a horrible noisy background I need to get rid of!

Nevertheless, it should be a bit quicker and easier next time!

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