Calibration update of the COMBO-17 CDFS catalogue

We present an update to the photometric calibration of the COMBO-17 catalogue on the Extended Chandra Deep Field South, which is now consistent with the GaBoDS and MUSYC catalogues. As a result, photometric redshifts become slightly more accurate, with < 0.01 rms and little bias in the delta z/(1 + z) of galaxies with R < 21 and of QSOs with R < 24. With increasing photon noise the rms of galaxies reaches 0.02 for R < 23 and 0.035 at R approximate to 23.5. Consequences for the rest-frame colours of galaxies at z < 1 are discussed.