A Great Spiral

This is M101, perhaps one of the best known spiral galaxies along with M31 and M81. Shot through the ED80, this image, taken over two nights, was made up from 28 x 5min luminance exposures through a CLS filter, and 7 x 5min each of R, G and B.

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!

First Light For A New Toy

I’ve been promising myself I’d do it for ages, and have now finally done it – bought a “proper” CCD for taking pictures. I now have an Atik 314L+, and last night had the first opportunity of trying it out. These pictures are both simply monochrome images taken without a filter through the ED80, but I do have the filter wheel and LRGB filters, along with a hydrogen alpha filter to try out once I get the power supplies sorted out!

First up is another attempt at M101. This is a stack of 30 x 3min exposures , and it looks like it could usefully do with a lot more. One of the things I did notice about the camera was its sensitivity – while focusing and positining the image in the centre of the chip, it was possible to see where the galaxy was with just a two second exposure. Although there was no detail visible, it definitely wasn’t starlike. So it looks like framing objects should be a breeze!

Just to round the evening off, I had a quick go at M3, which was nicely positioned. This is a stack of just 9 x 2min exposures, and confirms what a bright object this is. The next thing is to have a go at adding some colour into these – lots of opportunities for experimentation!!


A favourite target is always M101, one of several galaxies that has the nickname of the Pinwheel. This was taken last night and is a stack of 30 x 3min exposures at ISO800 taken through my 8″ LX200R with f/6.3 focal reducer. There’s still a colour cast across the image, not helped by the presence in the sky of the crescent moon, that I’ve been unable to remove satisfactorily, but it shows a reasonable amount of detail in the spiral arms.