Megacam Filter Transmission Curves


Sloan bandpass filters

Filter Filter only Total Total
Magellan u' Ascii Ascii Postscript
Magellan g' Ascii Ascii Postscript
Magellan r' Ascii Ascii Postscript
Magellan i' Ascii Ascii Postscript
Magellan z' Ascii Ascii Postscript

The total transmission estimate includes CCD quantum efficiency, reflectivity of primary and secondary mirrors, transmission of corrector and window lenses, and atmospheric transmission of 1.2 airmasses. The relevant columns in the table are

WAVE Wavelength in Angstroms
T Transmission of filter
WAVE Wavelength in Angstroms
EXTINCT Atmospheric extinction at 1.2 airmasses
R Reflectivity of aluminum
SOLGEL Transmission of a solgel surface
WINDOW Transmission of a window surface
THROUGHPUT Combination of reflectivity and transmission terms
TOTAL T+QE+Extinction+Throughput terms

Narrow band filters

The following narrow band filters are available. These are all constructed from 4 pieces of glass, so there is a cross through the center of the mosaic that suffers from modest vignetting. These filters must be requested in well in advance of your run so that they can be installed.

Center (nm) Bandpass (nm) Filter only
915 16 PDF


Megacam had 5 filters available when it was at the MMT.  Manufactured by Sagem, they are 300mmx300mmx10mm
and are interference coatings on clear or  colored glass substrates.

Plots of all filters

Ascii text files with transmission in percent at several radii(mm) from the filter center
Filter Filter only Total Total
MMT u' Ascii Ascii Postscript
MMT g' Ascii Ascii Postscript
MMT r' Ascii Ascii Postscript
MMT i' Ascii Ascii Postscript
MMT z' Ascii Ascii Postscript