HDF photometric zeropoints (flux corresponding to 1 DN/sec)

FILTER  chip   STMAG    ABMAG  VEGAMAG   FLAMBDA
F300W   1      19.47    20.78    19.44   5.927e-17
F300W   2      19.48    20.79    19.45   5.880e-17
F300W   3      19.48    20.79    19.45   5.871e-17
F300W   4      19.45    20.76    19.43   6.024e-17

F450W   1      21.52    21.92    22.00   8.948e-18
F450W   2      21.53    21.93    22.01   8.877e-18
F450W   3      21.53    21.93    22.01   8.863e-18
F450W   4      21.50    21.90    21.98   9.095e-18

F606W   1      23.21    23.02    22.90   1.880e-18
F606W   2      23.22    23.02    22.91   1.865e-18
F606W   3      23.22    23.03    22.91   1.863e-18
F606W   4      23.20    23.00    22.88   1.911e-18

F814W   1      22.90    22.08    21.65   2.504e-18
F814W   2      22.91    22.09    21.65   2.484e-18
F814W   3      22.91    22.09    21.66   2.480e-18
F814W   4      22.89    22.07    21.63   2.545e-18

For general reference, listed below are the conversions between AB, ST,
and VEGA magnitudes for the HDF filters (as computed by synphot).

FILTER	ABMAG-STMAG	VEGAMAG-STMAG
F300W	 1.31		-0.024
F450W	 0.399		 0.476
F606W	-0.199		-0.315
F814W	-0.819		-1.258