FISHEYE LENS SYSTEMS

• US 3,734,600 A
• Filed: 12/16/1971
• Issued: 05/22/1973
• Est. Priority Date: 12/24/1970
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Yoshiyuki Shimizu
• Inventors: Shimizu, Yoshiyuki
• Primary Examiner(s): Corbin, John K.
• Application Number:
  US05/208,639
• Time in Patent Office: 523 Days
• Field of Search: 350/216,215,214,196
• US Class Current: 359/723
• CPC Class Codes: G02B 13/04 Reversed telephoto objectives
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces

Abstract

A lens system comprises, in sequence moving from the object side, first and second negative meniscus lenses both convex to the object side, a biconvex lens, a negative meniscus lens cemented to the third lens, and fifth to eighth lenses including one or two negative lenses and cemented together so as to form two lens groups. An aperture stop is interposed between the fourth and fifth lenses. The lenses are arranged to satisfy predetermined conditions, thereby providing a fisheye lens system having a long back-focus two to three times greater than its focal length and yet having a compact construction.

Claims

1. A fisheye lens system comprising, as viewed in the direction from the object to the image, first and second negative meniscus lenses both convex to the object side, a third lens which is biconvex, a fourth lens which is a negative meniscus lens cemented to the third lens, fifth and sixth lenses and seventh and eighth lenses are cemented together, respectively, an aperture stop interposed between the fourth and fifth lenses, and a filter interposed between the fourth lens and the aperture stop, the lens system satisfying the following conditions:

Focal length f 100.0, Angle of field 180*, F/2.8, Back-focus 237.38 R1 +581.25 d1 17.5 n1 1.62041 Nu d 60.3 R2 +92.375 d2 70.0 R3 +546.875 d3 11.25 n2 1.62041 Nu d 60.3 R4 +95.625 d4 60.63 R5 +143.75 d5 45.62 n3 1.57501 Nu d 41.3 R6 -133.313 d6 10.0 n4 1.77279 Nu d 49.5 R7 -321.313 d7 3.13 d8 11.25 Filter n 1.51823 Filter d9 54.37 R8 +3312.5 d10 6.25 n5 1.52682 Nu d 51.1 R9 +200.0 d11 31.56 n6 1.5200 Nu d 70.1 R10 -173.75 d12 0.625 R11 +577.688 d13 31.25 n7 1.5200 Nu d 70.1 R12 -80.625 d14 5.63 n8 1.7552 Nu d 27.5 R13 -204.319 where R represents the radius of curvature, d the intervertex distance, n the refractive index, and Nu d the dispersive power.

2. A fisheye lens system comprising, as viewed in the direction from the object to the image, first and second negative meniscus lenses both convex to the object side, a third lens which is biconvex, a fourth lens which is a negative meniscus lens cemented to the third lens, fifth, sixth and seventh lenses are cemented together, an eighth lens which is biconvex, an aperture stop interposed between the fourth and fifth lenses, and a filter interposed between the fourth lens and the aperture stop, the lens system satisfying the following conditions:

Focal length f 100.0, Angle of field 180*, F/2.8, Back-focus 246.08 R1 +620.463 d1 15.873 n1 1.62041 Nu d 60.3 R2 +103.244 d2 76.190 R3 +438.095 d3 14.603 n2 1.62041 Nu d 60.3 R4 +89.206 d4 86.984 R5 +200.0 d5 53.333 n3 1.74950 Nu d 35.0 R6 -98.667 d6 24,126 n4 1.64831 Nu d 33.8 R7 -450.793 d7 3.174 d8 11.428 Filter n 1.51823 Filter d9 43.809 R8 +1666.667 d10 23.492 n5 1.51835 Nu d 60.3 R9 -79.619 d11 5.714 n6 1.74950 Nu d 35.0 R10 +151.111 d12 26.031 n7 1.5200 Nu d 70.1 R11 -156.317 d13 0.634 R12 +506.730 d14 17.778 n 1.5168 Nu d 64.2 R13 -218.876 where Rrepresents the radius of curvature, d the intervertex distance, n the refractive index, and Nu dthe dispersive power.

3. A fisheye lens system comprising, as viewed in the direction from the object to the image, first and second negative meniscus lenses both convex to the object side, a third lens which is biconvex, a fourth lens which is a negative meniscus lens cemented to the third lens, fifth, sixth and seventh lenses are cemented together, an eighth lens which is biconvex, an aperture stop interposed between the fourth and fifth lenses, and a filter interposed between the fourth lens and the aperture stop, in which the lens system satisfies the following conditions:

Focal length f 100.0, Angle of field 180*, F/2.8, Back-focus 240.33 R1 +620.463 d1 15.873 n1 1.62041 Nu d 60.3 R2 +103.244 d2 73.015 R3 +400.190 d3 14.603 n2 1.62041 Nu d 60.3 R4 +87.460 d4 90.158 R5 +189.968 d5 53.333 n3 1.744 Nu d 44.9 R6 -103.244 d6 23.492 n4 1.62041 Nu d 60.3 R7 -481.980 d7 3.174 d8 11.428 Filter n 1.51823 Filter d9 42.539 R8 +1666.667 d10 20.952 n5 1.51835 Nu d 60.3 R9 -75.936 d11 5.714 n6 1.74950 Nu d 35.0 R10 +148.571 d12 26.031 n7 1.52000 Nu d 70.1 R11 -156.317d13 0.634 R12 +506.730 d14 17.777 n8 1.51680 Nu d 64.2 R13 -219.993 where R represents the radius of curvature, d the intervertex distance, n the refractive index, and Nu d the dispersive power.

4. A fisheye lens system comprising, as viewed in the direction from the object to the image, first and second negative meniscus lenses both convex to the object side, a third lens which is biconvex, a fourth lens which is a negative meniscus lens, fifth and sixth lenses and seventh and eighth lenses are cemented together, respectively, an aperture stop interposed between the fourth and fifth lenses and a filter interposed between the fourth lens and the aperture stop, in which the lens system satisfied the following conditions:

Focal length f - 100.0, Angle of field 160*, F/2.8, BacK-focus 240.69 R1 +548.000 d1 16.0 n1 1.62041 Nu d 60.3 R2 +92.400 d2 70.0 R3 +578.000 d3 11.333 n2 1.62041 Nu d 60.3 R4 +93.866 d4 60.667 R5 +144.000 d5 49.333 n3 1.57501 Nu d 41.3 R6 -133.333 d6 13.333 n4 1.77279 Nu d 49.5 R7 -321.333 d7 3.333 d8 12.000 Filter n 1.51823 Filter d9 51.333 R8 +3333.333 d10 6.666 n5 1.52682 Nu d 51.1 R9 +200.000 d11 33.333 n6 1.52000 Nu d 70.1 R10 -180.000 d12 0.666 R11 +520.000 d13 33.333 n7 1.52000 Nu d 70.1 R12 -83.333 d14 3.333 n8 1.75520 Nu d 27.5 R13 -212.057 where R represents the radius of curvature, d the intervertex distance, n the refractive index, and Nu d the dispersive power.