The Dynamic PSF tool in Siril

[900SL]

I've probably only scratched the surface of what this cool little tool can do

Located in the hamburger menu, under onions and ketchup 'Image information' and 'dynamic PSF'

There's a bunch of selection and filter adjustments, including roundness, pixel size, etc.

It will calculate tilt based on FWHM across the frame, number of saturated stars, FWHM(x) and (y) etc

The default values are a little too wide, I found that the selection included some double stars (elliptical), and some very bright circular patches of nebulosity, but tightening up the size and roundness criteria removed these

Here's a screenshot of a single 6m Ha crescent sub

 

Edited August 17 by 900SL

[JonHigh]

If you haven’t already used it, it also works in tandem with the deconvolution function. 

Edited August 19 by JonHigh

[900SL]

On 19/08/2024 at 12:15, JonHigh said:

If you haven’t already used it, it also works in tandem with the deconvolution function. 

Cheers! Just found Deep Space Astros youtube on that. Only issue is that the Siril deconvo seems to generate a lot of noise (on the linear stack anyway.. not tried on a stretched image)

[Xilman]

In my experience almost all deconvolution algorithms amplify noise. Some generate it too but that is often an indication of a poor implementation!

The Maximum Entropy Method tends to produce smoother images but MEM is notoriously hard to implement and slow to run. I am sure that is no coincidence that Siril implements only the simple noise-amplifying algorithms. Maxim DL is the only program of which I am aware which provides MEM deconvolution.

If I am deconvolving for aesthetic appeal rather than scientific value I tend to run a de-noiser after deconvolving. Naturally, it is no use running a simple smoothing algorithm! FABADA works remarkably well and I am a great fan of that algorithm

 

Edited September 16 by Xilman
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