PyHdust filters

Wavelength in Angstroms!

Zero point levels

Band
Photometric zeropoint in ergs/s/cm2/A
(flux for zero mag in Vega system)
U U0 = 4.18023e-09
B B0 = 6.60085e-09
V V0 = 3.60994e-09
R R0 = 2.28665e-09
I I0 = 1.22603e-09
Z Z0 = 7.76068e-10
Y Y0 = 5.973e-10
J J0 = 3.12e-10
H H0 = 1.14e-10
K K0 = 3.94e-11
L L0 = 4.83e-12
M M0 = 2.04e-12
N N0 = 1.23e-13
Q Q0 = 6.8e-15
Paranal_VISIR.J122 Paranal_VISIR.J122_0 = 5.782e-14

Sources

SVO Filter Profile Service - filter standardization in the VO
http://svo2.cab.inta-csic.es/svo/theory/fps3/index.php?mode=browse
SkyCalc - ESO Sky Model Calculator (contains Photometric zeropoint in ergs/s/cm2/A)
https://www.eso.org/observing/etc/doc/skycalc/helpskycalc.html
ESO FORS filters (not in SVO)
http://www.eso.org/sci/facilities/paranal/instruments/fors/inst/Filters/curves.html
Wikipedia - Photometric system article
https://en.wikipedia.org/wiki/Photometric_system
NIRC2 Keck (not in SVO; no curves, only info)
http://www2.keck.hawaii.edu/inst/nirc2/filters.html
Other filters lists

http://www.astro.caltech.edu/~capak/filters/index.html

http://www.aip.de/en/research/facilities/stella/instruments/data

http://www.mso.anu.edu.au/~brad/filters.html

AstroSurf - comercial filters response
http://www.astrosurf.com/buil/filters/curves.htm