The SBIG ST-4  CCD camera, with controller unit.

The ST-4 can be used as an auto-guider or as an imaging camera, but not both simultaneously.  It is manufactured by the Santa Barbara Instrument Group (SBIG).   It has a chip that contains 192 by 165 pixels, each of which measures 13.75 by 16 microns.  On our 8-inch Meade f/10 telescope, it has a field of view of only 4 by 4 arcminutes.  It has an 8-bit A/D accuracy and is thermoelectrically cooled.  The ST-4 chip is used in its autoguiding mode in the ST-7 CCD camera, along with the larger chip that has a 16 bit accuracy.