Issues with Zwo filter drawer

[IDM]

Having recently bought an Optolong L Extreme filter I thought it would be best to get a filter draw to make sure I could easily and safely add or remove the filter. I was a little shocked when I discovered how much they cost but thought it would be a worthwhile investment over time. However since using it I noticed that something wasn't right. So as a n experiment I have taken the dark master image and stretched it (see attached). I assume that the rays on both the left and right are due to light creeping into the filter draw. I also took the images I had taken of IC443 and processed them without calibration to see if the raw data from the telescope was also affected and it was.

Do you think my conclusion is right and what should I do? I am happy to make some modest modifications but given the exorbitant price of the filter draw I am tempted top simply send it back as unfit for use. I would be grateful for any feedback and thoughts.

Kind regards,

Ian 

Edited March 2, 2022 by IDM
Typo!!

[Grant]

Those rays are amp glow on the filter sensor - very common with CMOS cameras and can be removed completely through calibration with dark frames - nothing to worry about 🙂

[Grant]

Better explanation here: https://astronomy-imaging-camera.com/tutorials/what-is-amp-glow.html

[IDM]

Thanks for the swift response and great to know that its not light leakage! I am surprised that I haven't seen it so pronounced previously as I am sure I have stacked and stretched images without dark frames before without seeing the amp glow so strongly. The Zwo article is very helpful, not least by saying to not use master bias frames. I was also have to check that I don't have dark optimisation selected in DSS and see how the images come out.

Thanks again,

Ian

[The Admiral]

54 minutes ago, IDM said:

Thanks for the swift response and great to know that its not light leakage! I am surprised that I haven't seen it so pronounced previously as I am sure I have stacked and stretched images without dark frames before without seeing the amp glow so strongly. The Zwo article is very helpful, not least by saying to not use master bias frames. I was also have to check that I don't have dark optimisation selected in DSS and see how the images come out.

Thanks again,

Ian

I'd also advise that you hold the filter drawer closed with an elastic band or some sticky tape, as they are prone to drop out! I had that happen with mine, and luckily there was no damage done as the drawer dropped to the concrete below.

Ian