UKIRT Exposure Time Calculator

UKIRT instruments:

Set one of the three parameters below to INDEF or leave it blank to compute its value based on the other input parameters.

Integration time in seconds:      Magnitude:      Signal-to-noise ratio:

Seeing (arcsecs):Aperture (arcsecs):
Airmass:Source type: Point-source Extended
Sky brightness: Signal to Noise contributions: Show Hide
For extended source, the SNR is computed per pixel, and aperture and seeing are ignored.

Please report problems to W.Varricatt (w.varricatt at
Interface is based on IRAF ccdtime task. Algorithm is based on "IR imaging photometry signal to noise calculations", P. Hirst, March 9, 2005.