Optical zoom and image-rotating system

Claim 2

A supplementary wide angle lens and image rotator comprising a front negative lens member concave to the rear, a rear positive lens member spaced therefrom, and a Pechan type image reversing prism as hereinbefore defined between said two members, all rotatably mounted in optical axial alignment, the axis of rotation coinciding with the external segments of the optical axis, said prism having a pair of closely spaced internal faces adapted to transmit the optical beam in a direction substantially perpendicular thereto, said internal faces each having a reflective coating thereon; said reflective coatings defining aligned uncoated areas providing an aperture stop substantially midway between the two lens members.

Claim 3

A wide-angle lens attachment comprising a froNt negative member and a rear positive member spaced therefrom and adapted to enclose an optical prism therebetween, which said two members are made up of five lens elements L1 to L5 substantially complying with the following table in which dimensions are relative in terms of a unit which may conveniently be an inch and in which R1 to R8 designate the respective radii of curvature of the lens surfaces,, t1 to t5 the axial thicknesses, s1 to s3 the axial separations, n the refractive indices for the D line of the spectrum and V the Abbe dispersion numbers: R1 +2.765L1 t1 .180 n 1.717 V 29.5 R2 - 8.333 L2 R3 + 1.429 t2 .080 n 11.575 V 41.3 s .065 R4 +2.500 L3t3 .080 n 1.575 V 41.3 R5 +1.429s2 .210 P1 & P2 tp 4.621 n 1.697 V 55.6 s3 .100 R6 -4.545 L4t4 .065 n 1.648 V 33.0 R7 - 23.530 L5 R8 - 1.961 t5 .100 n 1.572 V 57.5

Claim 4

A wide-angle lens attachment comprising a froNt negative member and a rear positive member spaced therefrom and adapted to enclose an optical prism therebetween, which said two members are made up of five lens elements L1 to L5 substantially complying with the following table in which dimensions are relative in terms of a unit which may conveniently be an inch and in which R1 to R8 designate the respective radii of curvature of the lens surfaces,, t1 to t5 the axial thicknesses, s1 to s3 the axial separations, n the refractive indices for the D line of the spectrum and V the Abbe dispersion numbers: R1 +2.765L1 t1 .180 n 1.717 V 29.5 R2 - 8.333 L2 R3 + 1.429 t2 .080 n 11.575 V 41.3 s .065 R4 +2.500 L3t3 .080 n 1.575 V 41.3 R5 +1.429s2 .210 P1 & P2 tp 4.621 n 1.697 V 55.6 s3 .100 R6 -4.545 L4t4 .065 n 1.648 V 33.0 R7 - 23.530 L5 R8 - 1.961 t5 .100 n 1.572 V 57.5