Residuals of forward coordinate transforms from MSA to FPA for the imaging mode on the detectors. Left panel: distribution in the detector focal plane. The four quadrants of the MSA are clearly visible, the five fixed slits are visible in the center area. Isolated shutters and slits are disturbed by bad pixels, in particular Q3 (top left). Right panel: histograms of residuals in pixels in i and j direction (top, middle) and absolute residuals (bottom). Shown in red are the confidence limits of 68.27% around the median at −0.023 and + 0.022 (i), and at −0.038 and + 0.034 (j), and the limit of 68.27% of absolute residuals (0.046).