The target tonight was the Landolt standard field SA 112, Subfield 1. That subfield has only three standard stars in it, but this field happened to go from airmass 2 to almost its minimum airmass of 1.47 during the roughly 2.5 hours of full darkness. That should allow for good atmospheric corrections and allow transformation from our instrumental magnitudes to the standard magnitude system.
Observing conditions were good, with no clouds apparent and decent seeing of 5-6 pixels FWHM.
Air temperature was around 80F and focus set to 2885.
I also tried a new observing sequence, based on something I read at the AAVSO: IRVBBVRI. The advantage of this sequence is that the effective time of each pair of observations (e.g. the two I observations) is roughly the same, because that effective time is the average of the two midpoints of the exposures (though really it should be an intensity-weighted average if the source is variable).