RETROCAM: A Versatile Optical Imager for Synoptic Studies
  We present RETROCAM, an auxiliary CCD camera that can be rapidly inserted into the optical beam of the MDM 2.4m telescope. The speed and ease of reconfiguring the telescope to use the imager and a straightforward user interface permit the camera to be used during the course of other observing programs. This in turn encourages RETROCAM's use for a variety of monitoring projects. 
Christopher W. Morgan, Paul L. Byard, D.L. DePoy, Mark Derwent,   Christopher S. Kochanek, J.L. Marshall, Thomas P. O'Brien ...