Master calibration images for ISIS

Forums Spectroscopy Master dark frame Master calibration images for ISIS

Robin Leadbeater

Hi Jack,

Take a number of long exposure darks, at least as long as your longest exposure and with the camera at the same temperature. (I normally try to take 20, using cloudy nights)

Median combine them and subtract the master bias (offset) (ISIS for example can do all this for you) The result is the thermal contribution from the camera, which can be scaled to correct any length exposure

This page describes the master images needed for ISIS (In French but Google translates well enough)

and this page (in English) describes how to generate generate them in ISIS

see section 3 – spectral calibration