Begining EAA - banding on image

Discussion of using SharpCap for Deep Sky Imaging
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sudipkch
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Joined: Fri Jun 28, 2024 3:22 am

Begining EAA - banding on image

#1

Post by sudipkch »

Hi,

I started to transition from visual to astro photography recently and it seems like a steep learning curve. Attached is a first decent image (at least for me:) ) for a star out of my balcony.

I like to get some help on understanding the cause of the black band I see on the left and bottom edges. With the left one being quite thick.

Have searched in forums but could not find something similar.
My equipment is an ES ED80 with a ZWO 585MC camera on an Az GTI over an EQ wedge

Thanks
Attachments
Altair1_Stack_32bits_100frames_261s.CameraSettings.txt
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Altair1_Stack_32bits_100frames_261s.jpg
Altair1_Stack_32bits_100frames_261s.jpg (323.06 KiB) Viewed 1362 times
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admin
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Re: Begining EAA - banding on image

#2

Post by admin »

Hi,

this is fairly normal - what has happened is that the image in view of the camera has shifted during the stacking (perhaps just drift, or the mount got knocked, or similar). The software largely deals with this, but once the image has moved, parts of the original image are no longer in view, so they stop receiving new image data from new frames and get darker, giving the black bands seen at the left and bottom.

Given the left hand one is quite wide, you may want to check how your tracking is working or for any other issues that might be causing the image to drift so much - in the 'Drift Graph' tab in live stacking you can see a graph that will help you tell if this was a gradual creep or a sudden jump - see https://docs.sharpcap.co.uk/4.1/#Drift%20Graph%20Tab

cheers,

Robin
ChrisR Oz
Posts: 224
Joined: Tue Sep 28, 2021 11:03 am
Location: Melbourne

Re: Begining EAA - banding on image

#3

Post by ChrisR Oz »

Interesting that you still see stars in the black bands and no star trailing. It looks a lot like a case I saw recently, where the Offset (Brightness) became effectively zero only in parts of my image. This was also a ZWO camera (294MC Pro). For me, this only happened in Still frame mode. If I use Live View mode, then all is well. What mode were you using?

Cheers, Chris.
Celestron EdgeHD 8, Focuser; iOptron CEM120 mount on pier; Starlight Xpress AO, OAG and Filter Wheel; ZWO 2400MC, 294MC/294MM Pro and 174MM mini; SharpCap Pro, PHD2, Televue Powermate 2x, Baader Neodymium, Astronomik CLS-CCD, ZWO UV/IR, Duo filters
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