Abstract: A panoramic zoom lens assembly of the type including a reflector lens spaced from the image plane of an optical recording device such as a film camera or video camera is disclosed. The zoom lens assembly includes a cylindrical housing having a transparent sidewall portion and an opaque sidewall portion with a reflector mounted in optical communication with the transparent sidewall zone. The reflector is provided with a symmetrical, reflective surface of revolution the axis of which is transverse to the image plane. An annular, objective lens assembly is mounted within the housing in a fixed position surrounded by the opaque housing sidewall portion. An intermediate annular lens is mounted within the housing for reciprocal movement along the reflector axis between the objective lens and the image plane. Displacement of the movable annular lens varies the focal length of the overall lens assembly.

Abstract: A sweep generator for producing a circular raster of curved scanning lines on the target surface of a video camera is disclosed. Each curved trace follows a substantially circular path through a scanning angle of 360.degree.. The circular raster is generated by horizontal and vertical scanning signals which are synchronized with the horizontal line frequency of a video receiver. The horizontal scanning signal is characterized by a constant amplitude component followed by a sine wave component, and the vertical scanning signal is characterized by a composite waveform including a constant amplitude component followed by a sine wave component which is shifted 90.degree. in phase with respect to the sine wave of the horizontal scanning signal.

Abstract: A method for operating a panoramic optical system to produce a shadow or darkened zone on the apex of a curved lens in order to eliminate undesirable optical interference in the region between the curved reflector and the focal plane is disclosed. The claimed method makes possible the accurate prediction of the diameter of the darkened zone around which the reflected image is annularly disposed, for a lens having a reflective surface of a given radius of curvature and for a specific location of the transparent/opaque border relative to the top of the lens. This makes possible the calibration of vertical displacement of an opaque sleeve for quickly and easily establishing a setting which will produce a darkened zone of a standard diameter.