Abstract: A panoramic imaging system, for monitoring a space, comprises a single camera and a dome-like convex mirror. The camera is mounted relative to the mirror so that at least most of the surface of the mirror is within the field of view of the camera. The mirror has an elevation gain, .alpha., greater than 3 and a profile which (a) ensures that radiation from at least most of the space is reflected by the mirror onto the image plane of the camera, and (b) satisfied the relationship, in polar co-ordinates,Sin?A+0.5(1+.alpha.).theta.!=C.r.?-0.5(1+.alpha.)!where C is a constant and A specifies the inclination of the profile to the optical axis of the camera at the point on the mirror which is closest to the aperture lens of the camera. The camera may be an electronic camera having a charge coupled device (CCD) sensor at its image plane, and the processed image of the space produced by the camera may be displayed on a monitor screen as a dewarped image.