Constant surveillance is often a problem in larger institutions. The Bank of England has solved this problem by creating a room from which key areas of the building can be centrally monitored.

Installing Camera Obscura "eyes" at key locations, each eye is a mirrored lense capturing images that are then reflected through a refractive network of mirrors and lenses, much like an elaborate periscope channeled through tubes threading through the buildings infrastructure. Each image from each "eye" is then projected onto a mirrored screen in the Camera Obscura room, providing a patchwork view of each location. The operator can operate lenses to focus and enhance one image or one section of one image to a large scale.

Should the operator require it a photograpic plate is slid through the lense before the projected image and the image is captured. If the operator is unavailable, the system is automated to capture images at timed intervals collecting a sequence of images over one night that can be stored in archives. Similarly, other security measures, such as pressure plates, alarm triggers or simply the opening of a door can activate the processing of a photographic plate so that unauthorised movement throughout the building can be captured.

Thus an unwary thief can be traced from his entry into the building to the act of theft and arrested upon this evidence.