MMT Imaging Exposure Time Calculator

Selecting a filter & instrument combination from the pull-down menu automatically fills in the appropriate pixel size, read noise, sky counts, and magnitude zero-point. Or, you can enter them manually if your favorite is not among the choices. For point sources you set the aperture size -- roughly double the expected FWHM should be close to optimal. Then set two of the bottom set of parameters and click compute to get the third. Megacam updated 3/05. SWIRC updated 02/07.

Filter:
 
Pixel size:
Read noise (e-):
Sky counts (e-/pix/sec):
Mag=15 (e-/sec):
Aperture diam ("):
Seeing FWHM ("):

 

  Point Sources

Point Source Brightness (mag):
Exposure time:
S/N:

 

  Extended Sources

Surface Brightness (mag/arcsec2):
Exposure time:
S/N: