Examples of JT detection efficiencies measured from 90-s exposures taken with a ﹩g^{\prime} ﹩ band filter on 2017 May 24 UT, under sunny conditions ∼ 1﹩\mathop{.}\limits^{^{\prime\prime} }﹩0 seeing. Each panel with the detector ID (in parentheses the name of the CCD chip) in the upper left corner corresponds to the actual layout of the CCD mosaic on the Suprime-Cam focal plane. CCDs #0, #3, #6, and #8 are located at the corners of the FoV of the Suprime-Cam. The solid lines are best-fit curves (see text).