Focuses ad nauseam despite perfect V (U) curve.

[nickstarboy]

Looks to be working perfectly, but then jumps to long side of focus and repeats, over and over again. at least 4 times before i stopped it.

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Probably/possibly related to error message showing in RH corner of screen….

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This will hopefully be fixed when parabolic/hyperbolic fit implemented!

[nickstarboy]

changed to 009 beta and it worked first time. however not sure this was a cure, may be coincidence.

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the original bug had been seen before sporadically.

[Yannick Dutertre]

I noticed the bug a couple of days ago, fixed here: https://bitbucket.org/Isbeorn/nina/commits/f02cc88d484ff57a0fbff846e5754e79bd353520?at=release/1.9

Should be int he next Beta.

[nickstarboy]

ah ok. is there a suggested work around? just done it again - this will stop any of my sequences from completing!

[Yannick Dutertre]

There are two issues:

• one with the focusing point logic, which will remeasure the same points multiple times during a single focus routine. I’ve fixed that in 1.10 (no nightlies yet) along with the fitting
• one with the reattempt logic - set that number to one in the options. Now what triggers the reattempt is that focus at start of AF routine, and focus at end of AF routine are very different the first time (more than 15%) - so it attempts again - and a bug makes it reattempt forever. With such a nice v-curve, the only reason I can think of that happening would be backlash when doing the final autofocus point. This seems to be confirmed by your last screenshot, where you can see the shape of the curve creeping to the left with the additional attempts.

So for the moment, set attempts to 1.

[nickstarboy]

for now ive just turned off autofocus and will hope its reached equilibrium!

its also doing a weird thing where it wont sync to the target - it finds the offset, reports its snyced the scope, eqmod agrees, but its in exactly the same place, for ever……

so i pointed it manually. may raise a ticket for this tomorrow.

[nickstarboy]

OK, will do - thanks!!!

[nickstarboy]

I think youre right about the backlash and the creep. The focuser is just about good enough for a single run through the v curve and back to focus, but repeated runs cause problems.

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Have set attempts to 1 and it seems to be working.

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Thanks again!