My attempts at astro imaging

Pixinsight Deconvolution tutorial


I have tried for years to get deconvolution working in various astro and non astro processing apps and never had ANY success, until now! After much reading of the docs and other tutorials I finally have a process that seems to work with my images…..

Deconvolution, what is it?  Think about it for a minute, if we could work out all the errors in our optics, and tracking, and atmosphere, we could apply the inverse of this to get a perfect image… Deconvolution attempts to do just that, the results do vary and the settings are VERY sensitive, but give it a try as I do think the results are worth the little bit of time it takes to get it right.

So, my method…. First up, this needs to be applied at the LINEAR stage

1. Create a synthetic Point Spread Function  – choose the Dynamic PSF Function from the Process menu

2. With your image, and a screen stretch only (remember this is to be applied at the Linear stage), double click on some stars to add them to the PSF function, say around 20, spread all over the image

3. click the Export Synthetic PSF button (Looks like a little ball)

4. Now, you want to create a star mask so…. apply the screen stretch to the histogram trasfer function then run the create star mask function, THEN…. undo the previous 2 steps so you are back to a linear image with a seperate star mask.

5. Open the Deconvolution process, enable de-ringing and local de-ringing, set the Local Support to the star mask you created previously

6. Now the tricky bit – Global Dark value in de-ringing, I usually scroll about the dark areas of the image and find the lowest values, then set the Global Dark value just lower than this, it does need a play around with but thats the good thing about Pixinsight and previews!

7. Leave everything else at default, other than the Iterations, I usually start at 10 and watch the preview, watch for ringing/dark areas starting to appear around the protected stars then back it off a few iterations

 

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