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yes, I had seen the pattern was similar to the light pattern, I was just confused as to why it wouldn't calibrate out. even the Ha was not a perfect calibration, as it looks like the center is a bit darker. It was just weird since my flat with a clear/L filter shows characteristics that each filter has to some extent. the Green, blue and Oiii have the bottom lines and vertical columns, whereas the red and Ha have that small little curve on the right side. So the patterns in both lights and flats seem wavelength dependent. People have been reporting similar weird flats and issues with the 294 series cameras I guess. Thank you so much for the reply, I really appreciate that you took the to bin and look at the images more closely. Also, I love that you are using ImageJ/FIJI, never thought I'd see that on an astronomy forum, what do you use it for?

I am using the OAG, I just retracted it to test the flats and rule it out. I don't think it was leaking light in this case since I have the whole setup covered anyway. I think it may be as the post above suggests, some kind of light leak from between the filter. Might have to find a way to fasten a gasket on the QHY filter wheel. Something like how ZWO gives. Thanks for the reply

I think it may be useful to include single light subs taken. Here are the Ha and Oiii stretched with STF in PI. I have also included Ha and Oiii fully stacked and calibrated using darks, flats and dark flats. Thanks.

Sorry, I should have given more details but was afraid my post would be too long. These flats were taken using an ipad screen with a white background. They were in my bedroom which was as dark as possible, but there was still some light from as it was not totally night time. I have tried to reduce any potential light leak by putting a towel on my setup, but unfortunately I couldn't think of a good way to cover the connection between the camera and filter wheel. In the past I had taken flats using the dawn sky and compared them with the ipad and I thought (key word on thought) that they seemed to be the same. I also have an EL panel coming in today so I can do more tests with that. All of these flats were taken with the oag fully retracted. edit: Many of these flats were under 2 seconds, some of them were under 0.1 seconds, especially for LRGB. Here is a link to a google drive with some of the raw files (5-10 each). https://drive.google.com/drive/folders/18rY_CqSxqStFk8JGYmhAXvON5OmhDv-l?usp=sharing

Hi all, I have been having issues with calibrating my images for several months now. I can't seem to isolate the issue, and I am in need of some help. My equipment: AT72edii with AT2FF field flattener QHY294m, QHY163C, CFW3 filterwheel and OAG. Filters: Baader LRGB, Chroma Ha/Oiii 3nm. Software: DSS for stacking (can try in PixInsight too) Things I know are not the problem: Field Flattener, OAG, camera? Things I cannot totally rule out: can the scope be an issue? I don't think my filters are an issue since rotating the camera yields the same flats being taken (I tried that on the Oiii, haven't tried it on the others), Filterwheel Here are some sample flats that are already stretched in PI, let me know if I should post tifs or maybe even the stacked images that show insufficient calibration. Thank you in advance.