ABSTRACT
Sensors, exposure, and calibration are inextricably linked. Electronic sensors are the enabler for modern astrophotography and without them it would be a very different hobby. Calibration deals with consistent errors and exposure are the key to reduce random errors. These errors are corrected by subtracting an offset and adjusting the gain. The practical upshot of this revelation is to add multiple exposures that do not saturate important areas of the image. Stars often saturate with long exposures and if star color is of great importance, shorter exposures will be necessary to ensure they do not become white blobs. Read noise is a key parameter of sensor performance and it is present in every exposure. It is made up of a mean and random value. Binning is a loose term used to describe combining several adjacent pixels together and averaging their values. It occurs within a CCD sensor or applied after the image has been captured.
