I do not have Pinpoint so FWHM is out.
Which is preferred HFR or HFD. I have ASTAP + D80 installed.
A 140mm refractor + reducer + QHY600M are used (if this matters).
Thanks
Steve Hoffman
There’s lots of arguments about the subtleties concerning FWHM vs HFR/D but there isn’t really any diff between HFR and HFD. It’s equivalent to saying I have a length of some yarn (HFR) or I have exactly twice that length of yarn (HFD). It is typically only important when using the result for further calculations. When using it as a comparison against itself (over time) it matters not.
What’s more important than the unit of measure here is what works best for your rig. ASTAP and SGPro use different approaches in measurement of a whole frame’s overall level of focus. They are typically evaluated empirically and, for most, it likely doesn’t matter one way or the other.