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Couple of moon pics and a star picture

PostPosted: Tue Nov 08, 2016 5:56 pm
by andrewscomputers
Hi all I took a couple of pictures of the moon on the 7th Nov of its first quarter and also a star picture,but the seeing was quite poor last night.Hope you enjoy.
Thanks
Andy

Re: Couple of moon pics and a star picture

PostPosted: Tue Nov 08, 2016 8:41 pm
by Gfamily2
I've got to say, but there's something odd about that star field image. Whereabouts in the sky is it?

Re: Couple of moon pics and a star picture

PostPosted: Tue Nov 08, 2016 9:12 pm
by andrewscomputers
Hi Gfamily2 i think it was just past cassiopeia but it was near lacerta as it was quite difficult to workout as the sky was not they clear last night.I put the video through registax and it ended up with this image once applying the wavelet,perharps my mono camera is playing tricks with my scope.
Thanks
Andy

Re: Couple of moon pics and a star picture

PostPosted: Tue Nov 08, 2016 9:25 pm
by Gfamily2
andrewscomputers wrote:Hi Gfamily2 i think it was just past cassiopeia but it was near lacerta as it was quite difficult to workout as the sky was not they clear last night.I put the video through registax and it ended up with this image once applying the wavelet,perharps my mono camera is playing tricks with my scope.
Thanks
Andy

Hi, yes.
There are a couple of points that make me wonder. It's hard to tell, but there seems to be very little difference in the brightness between the individual stars, which seems unlikely. In addition, there is what looks like a consistent 'alignment' of dots from bottom left to top right, which makes me think it might be an artifact of the processing.
How does the 'stacked' image compare with a single frame from the video? Have you tried stacking in an alternative program like AutoStakkert?
Could you take a dozen frames or so (not from the same section of the video) and stack them using different software such as DSS?

Re: Couple of moon pics and a star picture

PostPosted: Tue Nov 08, 2016 9:53 pm
by andrewscomputers
Gfamily2 wrote:Hi, yes.
There are a couple of points that make me wonder. It's hard to tell, but there seems to be very little difference in the brightness between the individual stars, which seems unlikely. In addition, there is what looks like a consistent 'alignment' of dots from bottom left to top right, which makes me think it might be an artifact of the processing.
How does the 'stacked' image compare with a single frame from the video? Have you tried stacking in an alternative program like AutoStakkert?
Could you take a dozen frames or so (not from the same section of the video) and stack them using different software such as DSS

Hi Gfamily2 I did run registax again and it seemed to put up to 590 alignment dots on the video so I rerun and have modified the image to this,but I was thinking that it could be noise on the gpcam creating the pixels instead of the stars for some reason.I have attached the 2 new images that I have created using the software.
Thanks
Andy

Re: Couple of moon pics and a star picture

PostPosted: Wed Nov 09, 2016 6:53 pm
by Aratus
Andy did you take any 'dark frames' and get your software to remove the frame from your image? Dark frames reveal 'noise' from your CCD at that exposure time. The 'noise' looks very similar to what you have here.

Re: Couple of moon pics and a star picture

PostPosted: Wed Nov 09, 2016 8:19 pm
by andrewscomputers
Aratus wrote:Andy did you take any 'dark frames' and get your software to remove the frame from your image? Dark frames reveal 'noise' from your CCD at that exposure time. The 'noise' looks very similar to what you have here.

Hi Aratus I found out today after telephoning the company that make my GPcam that my first image is noise from the chip and have told me to use a darkcorrection on the software to eliminate,once enabled should correct the problem hopefully as it captures.I found there is not much information on the web on a cmos camera and the best way to operate on the galaxies,stars,so when it is clear night again will have another attempt.
Thanks
Andy

Re: Couple of moon pics and a star picture

PostPosted: Thu Nov 10, 2016 7:26 pm
by Aratus
I did wonder. Noise is a feature of these cameras especially for long exposures on 'uncooled' cameras. You will need dark frames for every exposure time that you are likely to use. You can sometimes reuse them from night to night but changes in ambient temperatures can change the 'noise' so it is probably best to get fresh ones every night. Keeping the front cap on the telescope while taking the frame should be sufficient to get a dark frame. This is a steep learning curve but you will soon get the hang of it. I look forward to seeing your deep sky results.

Re: Couple of moon pics and a star picture

PostPosted: Thu Nov 10, 2016 8:50 pm
by andrewscomputers
Hi Aratus thanks for the advice,I did try the other day with the cap on the camera and I took 20 dark shots and enabled the dark sky correction on the software,it took out all the noise on the chip.So when I got some clear skys I will have another attempt.
Thks
Andy