Pancratic wide-angle objective

Claim 2

A pancratic wide-angle objective comprising: a stationary negative front component; a stationary multilens positive rear component; and an axially movable positive intermediate component between said front and rear components; said front component being a meniscus-shaped lens member with a concave surface turned toward said intermediate component and with an absolute focal length greater than that of said rear component; said intermediate component being a biconvex lens member with a focal length greater than the absolute focal length of said front component, the absolute focal lengths of said front component, said intermediate component and said rear component having a ratio of approximately 4:5:3.

Claim 3

An objective as defined in claim 1 wherein said front and rear components are separated by an airspace greater than the focal length of said front component.

Claim 4

An objective as defined in claim 2 wherein said airspace equals approximately twice the focal length of said rear component.

Claim 5

An objective as defined in claim 1 wherein the separation of said intermediate component from said front component substantially exceeds its separation from said rear component at both ends of its range of displacement.

Claim 6

An objective as defined in claim 1 wherein said front component is a single lens L 1 , said intermediate component is a signal lens L 2 and said rear component consists of a positive first lens L 3 , a positive second lens L 4 , a negative third lens L 5 and a positive fourth lens L 6 .

Claim 7

An objective as defined in claim 5 wherein said lenses L 1 - L 6 have thicknesses d 1 - d 6 , radii r 1 - r 12 and separations l 1 - l 5 whose numerical values, together with their refractive indices n d and Abbe numbers v d , are substantially as given in the following Table: Thicknesses and Lenses Radii Separations n.sub.d v.sub.d ______________________________________ r.sub.1 + 7.072 L.sub.1 d.sub.1 0.229 1.658 50.9 r.sub.2 + 1.972 5.530 f.sub.min l.sub.1 5.102 f.sub.M 4.516 f.sub.max r.sub.3 + 8.596 L.sub.2 d.sub.2 0.457 1.589 61.3 r.sub.4 - 4.856 0.014 f.sub.min l.sub.2 0.443 f.sub.M 1.029 f.sub.max r.sub.5 + 2.137 L.sub.3 d.sub.3 0.372 1.589 61.3 r.sub.6 + 14.894 l.sub.3 0.014 r.sub.7 + 1.425 L.sub.4 d.sub.4 0.500 1.589 61.3 r.sub.8 ∞ l.sub.4 0.104 r.sub.9 - 5.597 L.sub.5 d.sub.5 0.643 1.785 25.8 r.sub.10 + 0.768 l.sub.5 0.121 r.sub.11 + 4.705 L.sub.6 d.sub.6 0.286 1.691 54.7 r.sub.12 - 1.364 ______________________________________

Claim 8

An objective as defined in claim 5 wherein said lenses L 1 - L 6 have thicknesses d 1 -d 6 , radii r 1 - r 12 and separations l 1 - l 5 whose numerical values, together with their refractive indices n d and Abbe numbers v d , are substantially as given in the following Table: Thicknesses and Lenses Radii Separations n.sub.d v.sub.d ______________________________________ r.sub.1 + 14.316 L.sub.1 d.sub.1 0.286 1.589 61.3 r.sub.2 + 1.960 5.497 f.sub.min l.sub.1 5.011 f.sub.M 4.524 f.sub.max r.sub.3 + 5.234 L.sub.2 d.sub.2 0.458 1.589 61.3 r.sub.4 - 7.490 0.058 f.sub.min l.sub.2 0.545 f.sub.M 1.032 f.sub.max r.sub.5 + 2.434 L.sub.3 d.sub.3 0.344 1.589 61.3 r.sub.6 + 33.380 l.sub.3 0.014 r.sub.7 + 1.507 L.sub.4 d.sub.4 0.558 1.589 61.3 r.sub.8 ∞ l.sub.4 0.106 r.sub.9 - 5.485 L.sub.5 d.sub.5 0.573 1.785 26.1 r.sub.10 + 0.888 l.sub.5 0.129 r.sub.11 + 3.800 L.sub.6 d.sub.6 0.315 1.691 54.7 r.sub.12 - 1.722 ______________________________________

Claim 9

An objective as defined in claim 5 wherein said lenses L 1 - L 6 have thicknesses d 1 - d 6 , radii r 1 - r 12 and separations l 1 - l 5 whose numerical values, together with their refractive indices n d and Abbe numbers v d , are substantially as given in the following Table: Thicknesses and Lenses Radii Separations n.sub.d v.sub.d ______________________________________ r.sub.1 + 13.048 L.sub.1 d.sub.1 0.255 1.589 51.4 r.sub.2 + 2.107 5.452 l.sub.1 4.956 4.459 r.sub.3 + 5.226 L.sub.2 d.sub.2 0.454 1.589 61.3 r.sub.4 - 7.480 0.050 l.sub.2 0.547 1.043 r.sub.5 + 2.282 L.sub.3 d.sub.3 0.369 1.589 61.3 r.sub.6 + 31.295 l.sub.3 0.014 r.sub.7 + 1.412 L.sub.4 d.sub.4 0.496 1.589 61.3 r.sub.8 ∞ l.sub.4 0.099 r.sub.9 - 5.555 L.sub.5 d.sub.5 0.638 1.785 26.1 r.sub.10 + 0.755 l.sub.5 0.135 r.sub.11 + 3.444 L.sub.6 d.sub.6 0.284 1.691 54.7 r.sub.12 - 1.376 ______________________________________