variable brightness in subframes with a ASI294MC pro

finlelyhere

I have a ASI294MC pro that's about 3 years old. I've gotten good service out of it but lately I've noticed that when blinking through the frames there is a large difference in the brightness between frames. At first I thought just some passing thin clouds but then noticed that the amp glow, pretty prominent in a 600 sec subframe, also gets very dim along with the image. I've asked around and the only thing someone offered was perhaps a bad power supply. I changed the power supply but the issues persists. Does anyone have any idea what the problem could be? Thanx.

Tech@ZWO

finlelyhere Could you share some raw images with us? you can share them via google drive or others if the files are too large. thanks.

finlelyhere

Hi and thanks for the quick reply. I took 36 images each of the last two nights so I uploaded all of them. Blinking through them it looks to me like 49 of the 72 are definitely pretty dark compared to the other 23. You probably don't have to download all of them to see what I'm talking about. Haven't used google drive like this so I hope it works. Thanks for checking it out. The file is just labeled "Lights".

https://drive.google.com/drive/folders/18CAya9aczyzXAzfI6g-xjGKgfdC5Mq4A?usp=sharing

Tech@ZWO

finlelyhere It said i need permission to visit it, i just sent the request

finlelyhere

I think I authorized it. Of course, I thought I had done that the first time. Let me know if you have a problem.

Tech@ZWO

finlelyhere Got your images, they look fine. the different brightness is usually caused by the light source change.
You can check the higher brightness images, which have fewer galaxy details, because the light pollution obscures it, and also obscures the amp-glow.

finlelyhere

So, you're saying that it's light pollution causing the variation in illumination of the amp glow as well as the image? I'm in southern Arizona with Bortle 4 skies. In Pixinsight blink process the variation is dramatic. I'm about to shift over to a monochrome CCD camera and will see if, minus the amp glow, I get the same result. Thanx.