GB747228A - Improvements in or relating to anamorphotic optical systems - Google Patents

Abstract

747,228. Anamorphotic optical systems. COLEMAN, K. R., and TAYLOR, TAYLOR, & HOBSON, Ltd. June 23, 1954 [April 12, 1954], No. 10749/53. Class 97 (1). An anamorphotic system comprises two members each consisting of two refracting prism components having their generators parallel to one another and so arranged that an incident ray will be deviated in one sense by one component and in the reverse sense by the other, the prism generators in one member being arranged at rightangles to those of the other member and the members being such that an axial ray incident on the first member which emerges from such member in a direction substantially parallel to its direction of incident will emerge from the second member in a direction substantially parallel to such direction of incidence. The two members may be similar, the component prisms being simple or compound and being arranged, if desired, as described in Specifications 745,315 and 746,194. Fig. 13 shows the system applied to photography or projection, each prism member being formed of two compound prisms the front prisms C<SP>1</SP>, C<SP>2</SP> and C<SP>3</SP>, C<SP>4</SP> being arranged as shown before an objective K and the rear prisms D<SP>1</SP> ... D<SP>4</SP> being similarly arranged with their generators perpendicular to those of the first member. Light from one conjugate plane M<SP>1</SP> is collimated by a lens M before it falls on the prism system. The lens M may be replaced by two simple or compound lenses relatively movable axially to vary their effective focal length, or by the system shown in Fig. 17 comprising two negative lenses P<SP>2</SP>, P<SP>3</SP>, moved within two positive lenses P<SP>1</SP>, P<SP>4</SP> to vary the focal length of the combination. The prism components of each member may be moved angularly with respect to each other to vary the effective magnification of the system, the prisms being connected by suitable gearing or by cable and pulleys to ensure corresponding simultaneous movement of the four components. Numerical data are given, for one example in which each prism component is simple, or one in which each is formed of two prisms cemented together and for one in which the front component of each member is formed of two prisms and the rear component of three prisms.