par Sébastien Haller | Jan 17, 2026
Seeing calculator FWHM (arcseconds) = FWHM (pixels) × (Pixel Size in microns / Focal Length in mm) × 206.265 0.5-1.0″ = Exceptional Seeing1.0-2.0″= Good Seeing2.0-4.0″ = OK Seeing4.0-5,0″ = Poor Seeing5.0-6.0″= Very Poor Seeing FWHM [px]...
