Evening,
This is about an hour of 20ms exposures, unfiltered (so UV to IR) of the core of M13 with my standard DSO setup (12" newtonian on EQ8), but with a tiny ROI of 504x440 pixels. I used my ASI294MM which can be used unbinned with 2.3u pixels (I think most people use it binned - i generally do) to give a good resolution - 0.4" at newtonian focus, and this is 2x resampled in autostakkert to give 0.2" per pixel. The measured FWHM is 0.65" (about 3 pixels). FOV is 3.5 x 3.0 arc minutes.
Its not quite HST, but not bad! Coincidentally its almost exactly the same FOV as a widely circulated HST pic of M13, and my image is only about 8x worse resolution! Guess which is which? Maybe I'll do colour sometime....