Date: Sat, 18 Jun 2016 20:56:48 -0000 (UTC)
Subject: Re: [sloan-25mlog 3014] 2.5m obslog 20160617 (SJD 57557)
From: "Dmitry Bizyaev"
Hi Gordon,
this is good that you solved the problem quickly!
Just a few questions, to be sure we understand what happened
and how you fixed it:
>Had some issues with the guider. Normally when adjusting the focus and
.scale we
>adjust the focus and then the scale. While the scale is changing we get
>one or
>two guider images with exceptionally unfocused(donut shaped) stars which
>then
>automatically resolve once the scale change has completed. This time the
>guider
>froze with the stars unfocused(donut-ed). We had to manually bring the
>focus
>back in and continue the rest of the necessary scale changes before
>starting science.
- did you apply the recommended focus change all at once (e.g. delta=0.03),
or you did it by steps of no more than 0.01? Might it be a typo in applied
delta correction value?
- when the guider got stuck at showing donuts, did the scale got stuck also,
or it went to its predicted position? I mean, you applied certain "delta",
which had to send the focus to its predicted value, but the value did not
go all the way there, or it did go there.
- did you see a jump in the the focus value (after you started fixing the
donuts)?
Cheers,
Dmitry