[Dennis]

Originally Posted by luka

Hi everybody,

I am using a DSLR (Nikon D80) on a tripod to make some 50mm wide field images with 10s exposure which I would like to stack. Several questions:

1. When using Deepsky Stacker, the stacking of images is relatively straightforward but there are some kind of "dark trails" behind stars, as in the attached image which I have brightened to emphasize the trails. What am I doing wrong and how do I get rid of them? Darkening the image gets rid of them but it also gets rid of details.

Thanks

Hi Luka

I get similar “streaks” with my cooled ST7 CCD camera when I take short exposures, less than 20 secs at F10. I figured that it was due to noise as when I take longer exposures, over say 60 secs, the artefacts disappear as the Signal to Noise Ratio is better with longer exposures.

Cheers

Dennis