Lens Systems with Frontal Aperture Stops

The requirements for the aberration correction in lenses with frontal aperture stops (FASs) are determined. The theory of distortion and field curvature correction is examined in such asymmetrical optical configurations. Computed results for an orthoscopic telecentric objective of the OR-3 type are given. A design for an f/1·6 photographic lens with field 65° is given. Some conclusions for the trends in FAS system development are drawn. The theoretical results of the synthesis and aberration correction for this type of lens system are given.