“Incidentally, which exo are you trying.” Perhaps that is best kept firmly swept under the carpet for the moment.
Now trying again with WASP-65b. Predicted ingress is 23:52 with a depth of 0.0138 magnitudes. After much careful calibration 50 second exposures produce a SNR of~900 on an unfiltered CCD and imaging started at 23:00. My guess is that should give adequate precision (around 1.1mmag all being well) at a useful cadence. OK, it’s not in a standard photometric band but it’s close enough to GAIA-G and will do for a first attempt. I’ll be happy if anything decent looking shows up in the light curve.
Seeing is appalling right now, with stellar images at 8-15 arcsec FWHM. Strong north-easterlies blowing over the Canaries and as they pass over the caldera and cumbre a great deal of turbulence ensues down here at 760m altitude. The lucky guys at El Roque are above all that at 2600m. Perhaps it will improve later during the night but knowing my luck, it won’t.