So I use to use another program for culling my data but since the .xisf format can not do this anymore. So I tried using the script in Pix Insight and obviously have it completely wrong as it didn't write one file to the directory I set. I had it set for FWHM < 3 and know for a fact that a good deal of the raw data was rated at less that 1.50 arc seconds. So why the failure? What is a solid expression (s) to use to sort out the best data. I want only data below 3 arc second FWHM. Much of it is in the 1.5" range. Is it better to use the raw or calibrated images. If raw then I can still use the other program. The other program listed 179 images below 3" where PI listed 0. Something obviously wrong in my settings but no idea where to look.