Lowell Observatory Exposure Time Calculator (ETC)

Input any two (S/N, magnitude, exposure time) and obtain the remaining value.

Mode:
Exposure time for a given S/N and magnitude. Please provide:
             Magnitude:
             S/N ratio (> 0.1):

S/N for a given exposure time and magnitude. Please provide:
             Magnitude:
             Exposure Time (s) (> 0.001):

Magnitude for a given S/N and exposure time. Please provide:
             S/N ratio (> 0.1):
             Exposure Time (s) (> 0.001):

Bandpass:

Telescope/Instrument:
DCT/LMI
Hall/NASA42

CCD Binning Factor:

Seeing (arcseconds):

Lunar Phase (days):

Airmass:




Created by Phil Massey and Kathryn Neugent

Basic equations and assumptions can be found here.