AC4040 - Rectangular gradients

Yes, I've found that your suggestion works well. Dithering does seem to be important, and as you mentioned to me at AIC, using a larger dither definitely helps.

 

We have a full set of LRGB+Ha+SII+OIII supplied from you with our camera. I'm positive that what I'm seeing is not the quadrant effect.

 

Here is a drive folder. Includes red lights and flats and the darks for each.

https://drive.google.com/open?id=1vUouaQ-JHpbZC7bYXXe_V6IEw2Pe6959&authuser=mtlemmon.skycenter.remote@gmail.com&usp=drive_fs

note: it may take a little bit for all the files to appear as they are still uploading as I post this.

 

I've put a flat in each filter in the folder above.

Notably there is the pattern you described on the phone in all the filters that came with the camera. I also note that I can see it in the Schott GG495 filter that we received from a different manufacture which is interesting and possibly a very very tiny bit in the "OPEN" no filter. I'm going to get a really good average there and see if I'm just seeing things.

If you want to have fun we just got a diffusion filter (labelled as such) which has a wacky flat frame.

 

No reducer or corrector. It would be a StarChaser, AFW filter wheel, AC4040BSI. That's it.

 

Schulman yes. 32in f/7 5720mm focal length.

 

Travis, please give my regards to my old scope next door!
M.