My M27

[Ags]

I'm feeling a bit down tonight - DSS is turning all my images white, my mount is not tracking correctly, and my UHC filter is a bit rubbish!

Here is the last image I managed to drag from the teeth of DSS. I feel pleased with it because I managed to mostly process away the star trails. It was shot through my UHC filter, but looking at the odd shapes of some of the stars I think I will keep the filter for visual use only. There is some red data in the image despite the UHC filter, but it is lost in the noise. I will try M27 again soon without a filter.

[Ags]

I feel a bit happier now - I did 20 minutes of test exposures on M33 last night and got something recognizable. I'll do a longer run tonight.

[Ags]

Here is another effort, this time shot in RGB not with a UHC. The camera is unmodded and my exposure times were very short - but I got some hints of the red arcs in M27 and some fine structure!

The picture looks harsh because I had to process away a ferocious gradient. I'm still trying to figure out how to use IRIS to remove gradients. I tried various tricks like blurred layers to soften the image, but without much luck - any suggestions?

One thing I am very pleased about is that I have figured out how to stretch histograms in DSS - this removes the main limitation of GIMP.

[Dann]

Nice capture Ags.

May I ask, is the white border on your shots something you add yourself or an after effect of your camera/processing?

[Ags]

Thanks Dann - I am slowly learning... :-) I'm pleased there is some actual detail in M27 in the last capture - unfortunately you can't really see it in the downscaled version created by the forum uploader. I've added a cropped version so you can see my effort in all its 'glory'.

The border is a Gimp lens-effect to correct for the curved field of the ST80 I am using - it curves in the edges, leaving a TV shape. So the stars at the edges are still bloated (because they are out of focus) but at least they are round.

[Ags]

At the risk of seeming a bit obsessed with this image, I tried to apply the technique for star colors I've read about in Astronomy magazine. I've learnt that if stars get stretched too much, they turn white. But they also turn SmartiesTM colors if you clip away the LP without stretching. So i created a star layer and clipped away the LP, then adjusted the color balance and they pushed up the brightness to tone down the colors. I'm not too sure these colors are realistic, but i think they improve the image...

EDIT: Uploading a PNG as it turns out the JPG version loses all the star colors... There's a lot to learn.