Siril 0.99.8.1 can measure the average FWHM value of a FITS from the average PSF parameters of its stars. This is very useful.
However I compared this FWHM value to those obtained with other software (Moffat and Prism) and found quite different results.
I obtained with Siril much lower values.
- with Siril : FWHMx = 2.09” FWHMy = 1.92"
- with Moffat4 : FWHMx = 2.74”
- with Prism : FWHMx = 2.81”
Is Siril taking into account the correct focal length ?
I uploaded the FITS (M_81_Light_001.fits) on http://dl.free.fr/juuxQXNG7