Please see the UberCalibration entry in Algorithms for more information about the uber-calibration corrections. Note that if the NO_UBERCAL flag is set in the calibStatus, then the coversion factor is 0 and the magnitude is identical to that in PhotoObjAll. See also functions fUberCalMag and fUberCalibStatus. A sample join between PhotoObjAll and UberCal is as follows: select top 10 u.modelMag_r as urmag,p.modelMag_r as prmag from PhotoObjAll p, UberCal u where p.objID=u.objID AND u.calibStatus_r & dbo.fUberCalibStatus('PHOTOMETRIC') > 0 |