Date: Sun, 6 Mar 2022 23:29:18 -0000
Subject: Re: [sloan-25mlog 5921] Re: 2.5m obslog 20220305 (SJD 59644)
From: "Dmitry Bizyaev"
The autofocus was turned off for a purpose that time.
Its value was stable, but the small number of
useful stars in GFAs caused the fitting parabola
be wacky, which drove the focus value
back and fore around a stable figure.
This is not an issue.
Best wishes,
Dmitry
>> Oddly, the secondary focus values were set to correct automatically with
>> the auto-focus guiding function, but no incremental focus corrections
>> occurred within a full hour. First and last entries were:
>> 11:03:17 CmdDone: OBSERVER.dmbiz.tcc 19755 tcc set
>> focus=14.489999999999998 /incremental
>> 12:00:12 CmdStarted: OBSERVER.dmbiz.tcc 20058 tcc set
>> focus=17.939999999999998 /incremental
>
> If the focus isn't being auto-corrected, there might be some messages
> like: "Focus fit poorly constrained. Not correcting focus." in which case
> the auto-focus is not occurring by design.
>
> There's a cherno:focus_fit keyword that includes exposure number, several
> fit parameters, and then delta_focus (the negative of which is used in the
> focus correction, sometimes scaled). If the r^2 parameter (the sixth value
> in focus_fit) is  you should see the "Focus fit poorly constrained" messages. I can't
> remember what "flavor" of message those are, but if you have clicked all
> the icons in the upper-left of the boson Log window (debug, info, warning,
> error) they should scroll by if that's indeed the issue.
>
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