Software Newton Ring Removal. (Flashing Images!)

[Macavity]

Hurrah for the Sunspot(s)... 🥳

Just for fun, I was reprocessing one of my PAST sunpot animations.
I now get FAR better (automatic) alignment with ImPPG! Thanks! 🤟

I also fixed some variation in brightness of the image... manually.
I was wondering if there was any software to "equalise" images? 🤔

But *residual* NRs are still visible... when they FLASH on the screen?



Have been trying the "FFT - delete bits of transform - Reverse FFT"
thing in GIMP... But without much success. lol. The NRS are not
obvious in the FFT either?!? But maybe THIS has some prospects:

https://www.cloudynights.com/topic/594479-trick-for-removing-newtons-rings-fringes-from-images/

A splendid effort --- If somewhat lengthy and requiring thought! 😛

Another thing I notice in the image is THEN (probable!) NON use of
FLATS (the "bluebottle" flitting about to the right of the sunspot! lol).
But these are things I now do. I must fix the "wandering" HEQ5... 🤔

P.S. I always feel that *animations* should be "telling me something"!
I wonder what (if anything) this might be telling you (re. the Sun!) 🤣

Edited July 25, 2020 by Macavity

[Macavity]

Gave up on the FFT's! lol. But, as a "desperate move", tried something else... 😛
This may have reduced those residual Newtons Rings? Opinions welcome!

Edited July 26, 2020 by Macavity

[simmo39]

2 hours ago, Macavity said:

Gave up on the FFT's! lol. But, as a "desperate move", tried something else... 😛
This may have reduced those residual Newtons Rings? Opinions welcome!

I tried using FFT, couldnt get it to do anything, not very user friendly. You seem to have got someting to work though.

[Merlin66]

And the answer is.......?????

(I also found the FFT didn’t work too well. The best results so far have been with the T2 tilter)

what camera are you using?

[Macavity]

1 hour ago, simmo39 said:

I tried using FFT, couldnt get it to do anything, not very user friendly. You seem to have got someting to work though.

Thanks for the (positive) second opinion(s)!

No secret, this one. A old photographic technique with significant history
(I now see!): Contrast Masking! I use GIMP, but it's clearly adaptable...
https://www.gimp.org/tutorials/ContrastMask/

Truth be told, it's a technique I use with a LOT (Night too!) of images.
Works for 8-bit (Watec) Video Astronomy... which cannot be stretched
much... smoothing "off-center" FULL solar disks etc. Artificial Flats etc.  😎

P.S. The Camera is (of course?) the USB3 ICX445 (CCD) Chameleon 3.
It's inately pretty much free of NRs... Except for these disk animations!
After many years, I did follow that one simple recommendation... 🙂

Edited July 26, 2020 by Macavity