What on earth could be causing this? The z offset in mm is verified in the headers to be correct, AND config files are correct!
There isn't a 2nd filter out of focus, so this suggests its NOT a filter swap - does U-Bessell have to be inserted in a specific way in the filter holder?
IT #690 - reports out of focus, but IT closed as the offsets are correct in the config
these were Uspec and just fuzzier but not almost pupil de-focused like what we saw
IT #540 - reports B-Bessell out of focus - solution filter put in holder backwards
O.Kuhn checking closed-dome flats taken earlier and noticed the counts are not consistent with various filters - if U-Bessell were offset in the wrong spot, then its a domino effect on all the other filters in the wheel.
But...if U-Bessell is in empty slot, then g-sloan and r-sloan would be crossed with U-Bessell ... could the U-Bessell just not have been installed...
UT 07:27 - humidity 95.4% - closing
UT 08:11 - humidity 99.9%
UT 09:29 - humidity 93.9% - <1 deg from dewpoint - still closed
UT 10:17 - humidity dropped suddenly under 90% - but is slowly bounching back up
UT 10:29 - keep jumping back and forth over the 90% humidity line