My Rings in Images Problem is Solved!!!

[Spacehead]

Hi All,
I'd been having trouble with rings in my images - loads of people have helped out trying to explain them, with sensor problems, to bit depth, to compression, to DSS settings - but all to no avail.
Anyways - I decided it was all down to my flats.  I came to this conclusion after members here sent raw (flats and lights) files for me to study on my kit and I found that they too contained the rings, albeit to a lesser extent.
So I determined that rings are ok.  They must be.  BUT they must be cancelled out by good flats and maybe even helped along by darks.

Image 1 is how my stacked images look without flats - stepped - I was worried about the stepping - I hope you can see it.  
Although I was fairly confident in my "t-shirt" flats, they HAD been taken "the morning after" - and this required re-connecting the cam to the scope and running them off.
The orientation was locked and the viewfinder focus was locked - yet they just did not seem to work when stacking - the effects were - just odd and stripey - the rings were gone - but the image was horizontally striped instead - with bands about the same width as the ring gaps.
I have stretched it a bit to highlight the rings for the forum upload.

Image 2 is how my stacked images look now, but with new methods of flats and darks included in the stack - 26 darks and 30 flats.

Image 3 is my proudest moment ever - the processed image of the stack with flats and darks.

They absolute key to this - is this item.
https://www.amazon.co.uk/gp/product/B06XQ7WZKW/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

A flat tracing panel - I had to get the A3 as I didnt think the a4 would span the scope - just a tiny bit too small.
I power it with a lithium battery pack - and a USB cable - no need for mains power.  Sit it on top of the upturned scope before packing up and take the flats.

All in all - the job is done - I can now move on - cheers for everyones help.
:)
 

[Ruud]

Looks good!

[carastro]

Brilliant.  

Carole 

[geoflewis]

Great result, well done

Geof