Temporal evolution of an imaging observation of the XID2028 source. The natural seeing in the visible from the DIMM measurements is shown as a green line and varies between 0.8^′′ and 1.0^′′ over this ∼2 h observation. The individual points are the measured FWHM from fitting a Gaussian to a resulting 1min integration of six stacked frames. The red stars indicate the FWHM measured in the LUCI1 frames, the blue diamonds that in LUCI2. With this observation of an extragalactic source, no sky frames are taken, and no open-loop data is available. The one red star at 0.5^′′ is a frame marked with “paused”, indicating a laser propagation stop upon aircraft passage while still being closed on the tip-tilt star. The median performance on the LUCI frames over this full 2 h operation amounts to 0.26^′′ with LUCI1, and 0.25^′′ with LUCI2.