AutoFocus retry


I had an event today where my autofocus “missed” - I think probably my focus motor slipped/stalled (on this scope it’s a rack-and-pinion, but on another scope I have with a crayford and on that one the same could happen I guess with focuser slippage so that the calculated focus position is not actually achieved).

It would be nice, when the autofocus dialog says something like “The validation frame isn’t in accordance with the expected HFR” to be able to automate repeating the autofocus.

I could imagine something like an option in the autofocus settings, to say “If validation HFR is more than xx% higher than the expected HFR, repeat the autofocus up to N times”, at which point ideally, after say 2 or 3 tries, it would just give up, assuming that the reason for the poorer than expected focuser can’t be slippage at this point, and continue integrating frames, but probably with a crayford slipping for example, just trying again once would probably be enough to avoid screwing up a whole set of subs.The option for a %age higher than expected would let you set it to avoid minor occurances of less-than-expected focus accuracy (which do seem to happen somewhat regularly) from triggering a repeat focus run, so that for example with it set to something like 50%, then if expected HFR was 1.00 then an achieved HFR of 1.40 would be acceptable, but one of 1.80 would be a fairly clear case of either focuser slippage or something else gone wrong.

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+1 to this. I have no idea why this isn’t implemented already?

The general topic of HFR triggered focus (which is kind of similar) has come up before and straightforward to implement (IMHO) but I recall the consensus at the time was it caused more issues than it fixed. I’m trying to find the thread but what would be the proposal to overcome and not react to other factors that affect the HFR, like seeing and mist?