Trending plots for absolute efficiency as derived from standard star observations.

Two kinds of plots exist. The first set shows trending versus time of the absolute efficiency that is corrected for extinction and for losses due to the fibre size. These values should not depend on seeing. The second set of plots shows efficiency versus seeing; here the efficiency is only corrected for extinction and not for losses due to the fibre diameter.

Only measurements after 2018-09-01 are included in the plots.