MAG_PSF might not apply ZP correction

[YarinMS]

using the MS.plotRMS function we see that for the MAG_APER_3 the results might be higher than expected but the overall shape of the plot is expected (higher RMS for fainter targets).

for MAG_PSF the result is somewhat different and Eran suspect that it maybe not really applying ZP.

[EranOfek]

I can't see the problem in the code - need to run with a debuger. Also check if using MAG_PSF improve the relative photometric calib in: imProc.match.mergeCatalogs currently using MAG_APER_3...

[YarinMS]

I believe something changed? since running the same code over the same data yields better results