GB748910A - Improvements in or relating to a variable focus lens attachment for an optical objective - Google Patents
Improvements in or relating to a variable focus lens attachment for an optical objectiveInfo
- Publication number
- GB748910A GB748910A GB20913/53A GB2091353A GB748910A GB 748910 A GB748910 A GB 748910A GB 20913/53 A GB20913/53 A GB 20913/53A GB 2091353 A GB2091353 A GB 2091353A GB 748910 A GB748910 A GB 748910A
- Authority
- GB
- United Kingdom
- Prior art keywords
- lenses
- focal length
- members
- attachment
- objective
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B15/00—Optical objectives with means for varying the magnification
- G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B15/142—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having two groups only
- G02B15/1421—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having two groups only the first group being positive
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Stereoscopic And Panoramic Photography (AREA)
- Instruments For Viewing The Inside Of Hollow Bodies (AREA)
Abstract
748,910. Optical systems. COOK, G. H., and TAYLOR, TAYLOR & HOBSON, Ltd. July 22, 1954 [July 28, 1953], No. 20913/53. Class 97 (1). A variable focus attachment for an optical objective comprises two relatively movable members, one convergent and the other divergent, the equivalent focal lengths of the members not differing by more than 20 per cent of the greater whilst the radius of curvature of the outer surface of each of the two members is greater than the equivalent focal length of either member and the radius of curvature of the inner surface of each member is less than the equivalent focal length of either member and greater than one-third of the focal length of either member. The members may be simple or compound and the attachment may be used before the objective of one of a pair of stereoscopic cinematographic projectors to match the focal lengths of the two objectives of the projectors and of the taking cameras. Fig. 3 shows the attachment comprising simple lenses E<SP>1</SP>, E<SP>2</SP> placed before the amamorphotic lens system D<SP>1</SP>, D<SP>2</SP> described in Specification 740,642 which is itself placed before a camera objective F. The outer negative lens El is mounted in a cylindrical member G6 engaging a quick-pitch screwthread G5 on the lens cell G<SP>1</SP> so that by rotation of the member G6 the separation between the lenses E<SP>1</SP>, E' may be varied to adjust the focal length of the system. The two lenses may be made of the same material and to minimize aberrations the two outer surfaces may be slightly curved or one of each of the lenses made compound. Numerical data are given for a number of examples.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB20913/53A GB748910A (en) | 1953-07-28 | 1953-07-28 | Improvements in or relating to a variable focus lens attachment for an optical objective |
FR1110863D FR1110863A (en) | 1953-07-28 | 1954-07-26 | Variable focus lens system for an optical lens |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB20913/53A GB748910A (en) | 1953-07-28 | 1953-07-28 | Improvements in or relating to a variable focus lens attachment for an optical objective |
Publications (1)
Publication Number | Publication Date |
---|---|
GB748910A true GB748910A (en) | 1956-05-16 |
Family
ID=10153919
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB20913/53A Expired GB748910A (en) | 1953-07-28 | 1953-07-28 | Improvements in or relating to a variable focus lens attachment for an optical objective |
Country Status (2)
Country | Link |
---|---|
FR (1) | FR1110863A (en) |
GB (1) | GB748910A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2956475A (en) * | 1958-07-21 | 1960-10-18 | Bell & Howell Co | Wide angle lens attachment |
FR2370993A1 (en) * | 1976-11-15 | 1978-06-09 | Bolex Int Sa | OPTICAL SYSTEM WITH REMOVABLE POSITIVE FIRST PART AND ADJUSTABLE PANCRATIC SECOND PART |
GB2532407A (en) * | 2014-09-19 | 2016-05-25 | Jeffrey Barlow John | Focusing attachment |
-
1953
- 1953-07-28 GB GB20913/53A patent/GB748910A/en not_active Expired
-
1954
- 1954-07-26 FR FR1110863D patent/FR1110863A/en not_active Expired
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2956475A (en) * | 1958-07-21 | 1960-10-18 | Bell & Howell Co | Wide angle lens attachment |
FR2370993A1 (en) * | 1976-11-15 | 1978-06-09 | Bolex Int Sa | OPTICAL SYSTEM WITH REMOVABLE POSITIVE FIRST PART AND ADJUSTABLE PANCRATIC SECOND PART |
US4174153A (en) * | 1976-11-15 | 1979-11-13 | Bolex International Sa | Varifocal objective with focal length adjustment |
GB2532407A (en) * | 2014-09-19 | 2016-05-25 | Jeffrey Barlow John | Focusing attachment |
Also Published As
Publication number | Publication date |
---|---|
FR1110863A (en) | 1956-02-17 |
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