That would work… subframes. Put my vote in for that. Are you talking one subframe or many?
I still can’t get my head around the how the mean HFR per frame / position (without excluding the middle), maximizes the best focus in the two models. Oh, not sure if you clicked on the picture, there is some cutoff unless you click it.
Let me see if I have this straight (very simple analogy), consider moving the focuser +, this would cause all of the numbers to increase by one. Do the same + move and the numbers go up one more. Do the same in the reverse a few steps and when the mean is the smallest, you have the best focus with the V shaped graph.
1 represents perfect focus. The higher the number, the worse the focus.
The one on the left has a higher mean HFR, fewer 2s and 1s and lots of 6s. All stars will either be perfectly focused (only one 1) and the rest will be either over focused or under focused depending on initial focus.
The one on the right (excluding the middle) has way more 1s and 2s and no 6s Some stars will be slightly under focused and some will be slightly over focused.
I’ll do some more thinking… Thanks for getting back so quick. Again, I really like SGP. A total bargain.