Vertical Banding ToupTek ATR3 CMOS 26000 KPA · Eric Maurício · ... · 3 · 218 · 4

iApolo 0.00
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Hello all, I hope you're doing great.

I've purchased the Touptek2600c (tsoptics rebrand) around 2 or 3 months ago, as per usual, the weather wasn't cooperating, so I had to wait arund a month before I could start shooting. My plan for clear nights with little to no Moon, was to shoot the Shark Nebula, and so I did. 

After I got around 6h of data, I started to have a go at it in Pixinsight, and the problem first appeared. As I apply the Auto Stretch, I noticed vertical banding with alternating magenta and cyan cast, like so:

ldn1235 stretched saturated.jpg
This is a 18h stack, with no calibration frames, with ABE and Spectrophotometric color calibration applied, StarXterminator then saturated to enhance the issue. 
My acquisition process is as follows: 300s subs, 100 gain, 50 offset, at -15ºC. High Gain Mode enabled, Dew Heather on, although I don't think the camera as one, Ultra Low Noise Enabled. I dithered every frame.


Solutions that I've tried: Obviously I started by including calibration frames, darks, flats, and dark flats, none of them resolved the issue. Then I thought that, since I don't get the banding using the L-Ultimate filter, it could be a filter problem, so I removed the Svbony IR/UV cut filter, tossed all the frames that I had previously taken and shot again. Ended up with the picture above, so I guess it isn't the filter, but I cannot reproduce the issue, using the exact same acquisition process and stacking, with the L-Ultimate filter. 

nebula crescent starless.jpg
This is around 9h with the same acquisition and stacking technique. 

Since I'm aiming at an LDN, I thought that it could also be that I'm clipping my blacks, so I increased the offset to 200, same result.
Then, I tried with 60s, and after that, 120s subframes, because I could probably be saturating the pixels and getting the pattern as a result, nothing changed.

I debrayed a single frame, stretched it, and the pattern (I think), is barely visible.
shark single.jpg

My theory is that pixels that don't get enough signal tend to form a patter noise with those colors, it's the only thing that I can think about, but I have no idea anymore, dark frames should enhance the issue and correct it.

dark debrayed .jpg
300s dark frame, debrayed, stretched.

If anyone as any idea what the problem seems to be, or as any input on the situation, I'd love to hear it.

Thank you and Clear Skies.
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wittinobi 0.90
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Hi,
if you use NINA, you can try to decrease the USB-Speed to 2 or 1.

Best Regards
wittinobi
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iApolo 0.00
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Hi,
if you use NINA, you can try to decrease the USB-Speed to 2 or 1.

Best Regards
wittinobi

USB speed was set to 2, will try 1, hopefully I can get some hours tonight and see if it helps.

Thank you!
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Shinpah 1.51
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I know several people, myself included, who have had horizontal banding appear in touptek 571 (Risingcam) cameras. Dark frames don't correct it because it jumps around from exposure to exposure. One of them (https://www.astrobin.com/users/justintastro/) had his banding go away from changing the USB traffic setting in NINA only for it to come back again with a vengeance months later - updating NINA to 3.0 for him has fixed it so far (which doesn't really make sense, but if it works it works).

Starxterminator will also make colorful tiles in your images if you push the data too hard - so make sure you're not inducing banding in that manner.
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