Bob, the plan log gives FWHM information about each image like this:

04:29:14 Image FWHM is 2.5 arcsec (2.00 pixels)
04:29:14 (avg FWHM = 2.98 arcsec)

In photometry, it is very important that the airy disc not cover too few pixels. Ideally not less that 2.5, 2 is really pushing it. As you can see from the above some of my images in my new system are at least bordering on too tight. What is the difference between "image FWHM" and "average FWHM"? One number here is livable, the other not.

Also, in this vein, how feasible would it be to add an option to defocus if the results of a image fell below a certain level, i.e. rack out focus X steps if the FWHM falls below Y? Probably more complicated than the current feature that commands a new focus run if the airy disc grows more than X.