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Optical distortions for SP2 and SP3

Posted: 27 Oct 2022, 14:24
by fabdev
Hello, Astroart 8 SP2, released last month, included an option to correct non-linear optical distortions for image stacking. Distortions can be an issue with some optics when the field of view is higher than 0.5 - 1 degrees.

Astroart 8 SP3 (to be released next year) now supports optical distortions also for astrometry, following the FITS SIP standard. If you like to use this function now and download a beta version, please contact me by email at:

FITS SIP uses a polynomial function to represent the distortions. For example, for a 3┬░order polynomial:

x' = A00 + A10x + A01y + A11xy + A20xx + A02yy + A21xxy + A12xyy + A30xxx + A03yyy
y' = B00 + B10x + B01y + B11xy + B20xx + B02yy + B21xxy + B12xyy + B30xxx + B03yyy

For more information see: ... n_v1_0.pdf

Re: Optical distortions for SP2 and SP3

Posted: 18 Nov 2022, 14:17
by AstroBernd
Hello Fabio,
Very interesting option for large-area shots with short-focus lenses. I couldn't find the option in SP2. Where is it? Somewhere in Preprocessing?

I am also interested to test it out for SP3.
Good stuff!

Re: Optical distortions for SP2 and SP3

Posted: 18 Nov 2022, 15:26
by AstroBernd
I found it in pre-processing and alignment. Awesome! Seems to work on my Hyperstar images and improves stars.
Will test it on DSLR images with short focal lenses as well. That will put it to a stretch :-)