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 objective

Info

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
Application number
GB20913/53A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Taylor Taylor and Hobson Ltd
Original Assignee
Taylor Taylor and Hobson Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Taylor Taylor and Hobson Ltd filed Critical Taylor Taylor and Hobson Ltd
Priority to GB20913/53A priority Critical patent/GB748910A/en
Priority to FR1110863D priority patent/FR1110863A/en
Publication of GB748910A publication Critical patent/GB748910A/en
Expired legal-status Critical Current

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.
GB20913/53A 1953-07-28 1953-07-28 Improvements in or relating to a variable focus lens attachment for an optical objective Expired GB748910A (en)

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)

* Cited by examiner, † Cited by third party
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

Cited By (4)

* Cited by examiner, † Cited by third party
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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