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QHY 183c Background Pattern Issues

QHY 183c Background Pattern Issues
« on: April 14, 2021, 03:04:37 PM »
Hello, I've been having issues with strange background patterns in the images taken with my 183c. It forms a grid like pattern in my images. Calibration frames are only marginally effective at removing the issue. I have reached out to several online astrophotography groups with limited success. At this point I have reached the limit of my knowledge and have run out of things to try. Dark frames are taken in a sealed storage container at the same gain, offset, and temperature as the light frames. Flats and dark flats are also taken at the same gain, offset, and temperature as the lights. A white t-shirt was used with an iPad as the light source. Images were captured using APT, stacked in DSS, and processed in Photoshop cc.

I would greatly appreciate any help anyone has to offer.

Best Regards,
Owen

I have attached an image that highlights the issue.
Here is the google drive link.
https://drive.google.com/drive/folders/17nY2abK68uWl7g45useK8wXmG9fVu_RE?usp=sharing

Note: this image was not calibrated with darks and flats or processed to reduce noise, gradients, amp glow, etc. Calibration frames take care of most of those with no problems. This was done to highlight the issue.

Image details:
Lights: 45x180s (guided, dithered) | gain11 | offset 31 | -15c
Scope: William Optics Zenithstar 61
mount: Heq5 pro
Filter: Baader Moon and Skyglow

APT version: v3.87
SDK version: 20.2.28.0
Ascom driver version: 0.1.51.44
« Last Edit: April 15, 2021, 05:03:13 PM by Omesserly »

Yuki

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Re: QHY 183c Background Pattern Issues
« Reply #1 on: April 15, 2021, 11:32:24 PM »
Hi,

Can you send FITS to us for check?

My email address is zyq@qhyccd.com

Best Regards