Comet 103P Hartley and the Double Cluster

British skies were cloudy over the best couple of days for catching the comet and the Double Cluster together, but on 10 October I got them together with the 100mm macro at f/2.8. I made three 20-second exposures at ISO1600 and combined them in Deep Sky Stacker. I'm still a beginner with DSS and seem to have ended up with no colour in the stack, whereas the comet is clearly green in my originals. I used Photoshop to improve the sky and remove most of the vignette. I didn't really mean to end up with such a dark sky (it's still not completely black), but I'm not unhappy with it. For those unsure, the comet is at centre bottom.

Careful (eye straining) comparison of the same area on Wikisky.org shows I've reached mag 13.5 on the original stack. There's a lot of stars in this area of the sky!

cool, thx for posting!

-is this a crop?
-how'd you dial in the exact location? Just shoot @ Perseus?

Might be clear here in SE Mich, Magnitude 4.6 according to Heavens-above, so I'll be out shooting before the moon rises, maybe 10:30pm or so....

Thanks. It's a slight crop, just to get over the edge artefacts caused by stacking. Aiming was a bit of trial and error. The exposures were driven on a home-made equatorial.

Where did you go to shoot that then Mark, not much round here in the way of dark skies.

You're right there Ken. It was taken from my garden, but there was quite a bit of light pollution in the originals. Unfortunately, removing it has taken out all the colour. There are lots of ways of processing shots like these and I'm still only just exploring some of them.

I've been trying different things with these images. This time I manually combined the three in Photoshop CS5 and then tried lots of steps to get rid of the vignette and the light pollution. I have at least preserved the colours of the stars and the comet, but rather lost control of the sky colour, which retains a hint of pollution in the centre and then gets strangely magenta towards the corners. It's not too far from what I was trying to achieve though.

I'd be happy to hear any pointers to ways of achieving what I was trying.