Subframe selector

[AstroDude]

when using SNRweights  on the plot of the stars, is the top stars better then the bottom ones ... or is 0.55 better then 0.71?
im lost ...
some said the lower your SNR weights, the better the stars for choosing a reference in batch processing.
here is the comment :

When first pointing out the sorting of frames by SNRWeight, the frames you point to as best in the plot are actually the worst, as, unlike FWHM, the lower the value (bottom of the plot), the worse the SNR.?

[John_Gill]

Hi,

With SNR the higher the value the better, but with Eccentricity (star roundness) and FWHM the lower the value the better.  So your best selection is a an image with high SNR and lowest Eccentricity and/or FWHM.  If there are a number of images with similar high SNR then I choose the image with the lowest Eccentricity and if there is only one image with high SNR and the Eccentricity and FWHM are wildly different then SNR wins.

Remember that satellite trails/clouds can increase the SNR in an image so "Blink" the image stack first to weed out the bad ones.

Look up
John