Author Topic: Vertical band in image  (Read 2045 times)

Offline alanrock

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Vertical band in image
« on: 2018 September 17 16:11:15 »
I have taken 50 images each 15 seconds long and stacked them using BPP. I used (appropriate)darks, flats and bias frames. after BPP, I get an image with a vertical band in it, and I'm wondering if anyone can tell me where this might be coming from--I've attached the resulting image, which I have stretched like crazy in order to show what I'm talking about. Any ideas? BTW, I have another image taken on the same night which does not display this symptom.
I'm using SGPro for acquisition, and a ZWO ASI183 Pro cooled OSC camera cooled to about -15C. Let me know if I need to provide any other info.
Thanks!
Alan

Offline ngc1535

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Re: Vertical band in image
« Reply #1 on: 2018 September 17 20:14:32 »
Wow... that is odd. That certainly looks electronic. Did it happen to be something that appears in either your biases or your darks? (Did you examine them?)

On another note- the stars look diffracted. I don't know what telescope you used...but if I saw images like that- it looks like you are looking at the side of something (close) like the inside of an enclosure/dome. The mirror doesn't look fully illuminated based on my experience.

-adam

Offline alanrock

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Re: Vertical band in image
« Reply #2 on: 2018 September 17 21:06:56 »
I looked at the flats, the biases and the darks (not every single one, but samples), and they all look ok. None of them show the banding.

The diffraction spikes are from the cables; I'm using a Hyperstar and this is typical if you don't make any effort to route the cables in such a way as to not create spikes. I'm not too worried about those. The band is a lot more concerning to me.

Offline sharkmelley

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Re: Vertical band in image
« Reply #3 on: 2018 September 18 02:30:53 »
Very odd.  I think you should speak to ZWO.

Mark
Takahashi Epsilon 180ED
H-alpha modified Sony A7S
http://www.markshelley.co.uk/Astronomy/

Offline alanrock

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Re: Vertical band in image
« Reply #4 on: 2018 September 18 13:06:14 »
The individual subs look perfectly fine though.

Offline pfile

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Re: Vertical band in image
« Reply #5 on: 2018 September 18 14:08:51 »
sometimes you can't see subtle problems in a subexposure due to the noise...

rob