Comet stacking and removal of stars

[dnewbury]

I've been trying to stack a set of 10 comet images of 1 minute exposure following Harry's tutorial. However, I cannot seem to remove the stars. I have played with different options for Rejection Algorithm and Sigma High, however no luck. Any suggestions on how to tackle this? Perhaps my exposures just don't have enough separation in the star trails.

I did find this thread, but had trouble following some elements of the process (I need to brush up more on Pixel Math!). Plus the thread is a bit old and I'm wondering if the tools/processes might have changed since then?

http://pixinsight.com/forum/index.php?topic=2008.15

Thanks for any assistance.
Dave

[dzso.bacsi]

Hi,

Maybe following an other good tutorial (or relevant parts of it) might help:
http://pixinsight.com.ar/en/info/processing-examples/38/lovejoy-comet.html

Cheers

[dnewbury]

Hi dzso.bacsi,
Thanks for posting that link - there's some great material and detail there.

Unfortunately, I still get stuck at the stage for removing stars. Have played some more with Sigma High (and Low) in the II Pixel Rejection (2), however no luck. Best I can achieve is partial removal of stars. Instead of round or oblong stars, they are polynomial/odd shaped. I guess the algorithm is removing parts of the star, but not all.

Perhaps I'll have to take another go at capturing images of this targer, but separate each image with a time delay (I've seen reference to others doing this, for the same reason).

Dave

[Alejandro Tombolini]

but separate each image with a time delay

Hi Dave, That's right, you need more separation between images. In a large set of images you can pick some of them, ex 1, 3, 5,...n or 1, 4, 7,...n depending of the need (brightest stars will influence that), but you have only 10 images which will not allow you to do that.
Saludos, Alejandro.