Observing conditions and AO performances in IRDIFS observing mode: Strehl ratio as a function of the seeing measured by SPARTA (top-left). Strehl ratio as function of the atmospheric coherence time estimated by SPARTA (top-right). A linear fit is overlaid in red in the top figures. Strehl ratio as function of the star V magnitude (bottom-left). The blue data points represent the data taken with coherence time smaller than 3 ms. Histogram illustrating the repartition of the observations (including multiple observations of the same target) as function of the star magnitude in V, shown in dark blue, and H-bands, shown in light blue (bottom-right). The apparent high number of observations of R = 3.5 stars is an artificial effect that is due to the high number of observations targeting Beta Pictoris.