JPS5587118A - Focusing method which prevents change in angle of view - Google Patents

Focusing method which prevents change in angle of view

Info

Publication number
JPS5587118A
JPS5587118A JP16354678A JP16354678A JPS5587118A JP S5587118 A JPS5587118 A JP S5587118A JP 16354678 A JP16354678 A JP 16354678A JP 16354678 A JP16354678 A JP 16354678A JP S5587118 A JPS5587118 A JP S5587118A
Authority
JP
Japan
Prior art keywords
lens group
angle
focusing
view
constitution
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.)
Granted
Application number
JP16354678A
Other languages
Japanese (ja)
Other versions
JPS6152444B2 (en
Inventor
Kazuo Tanaka
Sadahiko Tsuji
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.)
Canon Inc
Original Assignee
Canon Inc
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 Canon Inc filed Critical Canon Inc
Priority to JP16354678A priority Critical patent/JPS5587118A/en
Priority to DE19792950951 priority patent/DE2950951A1/en
Priority to US06/105,089 priority patent/US4336983A/en
Publication of JPS5587118A publication Critical patent/JPS5587118A/en
Publication of JPS6152444B2 publication Critical patent/JPS6152444B2/ja
Granted legal-status Critical Current

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Abstract

PURPOSE: To eliminate the change in the angle of view at the focusing with a simple constitution by making the back focusing of the system provided on the image plane side than the movable group for the purpose of focusing equal to the exit position of the entire lens system.
CONSTITUTION: The 1st lens group 11 movable at the focusing, 2nd lens group 12, iris 14 and 3rd lens group 13 are subsequently disposed from the object side and the angle of view when the subject distance is infinite is let ω∞. Here, the angle of view when the suject 17 away by S1 from the 1st lens group 11 is focused by moving x the 1st lens group 11 is let ω. With this constitution, the back focus Bf of the optical system integrating the 2nd lens group 12 and 3rd lens group 13 and the exit pupil 15 of the entire system are equal. Hence, the main beam becomes parallel with the optical axis in the state that it emits from the 1st lens group 11 and enters the 2nd lens group 12 and since the exit pupil 15 position is always in a fixed position, ω becomes equal to ω∞, thus, the change in the angle of view owing to focusing may be eliminated.
COPYRIGHT: (C)1980,JPO&Japio
JP16354678A 1978-11-25 1978-12-25 Focusing method which prevents change in angle of view Granted JPS5587118A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP16354678A JPS5587118A (en) 1978-12-25 1978-12-25 Focusing method which prevents change in angle of view
DE19792950951 DE2950951A1 (en) 1978-12-25 1979-12-18 PHOTOGRAPHIC LENS WITH STABILIZATION AGAINST AN IMAGE ANGLE CHANGE DURING FOCUSING
US06/105,089 US4336983A (en) 1978-11-25 1979-12-19 Photographic objective stabilized against change of angular field during focusing

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16354678A JPS5587118A (en) 1978-12-25 1978-12-25 Focusing method which prevents change in angle of view

Publications (2)

Publication Number Publication Date
JPS5587118A true JPS5587118A (en) 1980-07-01
JPS6152444B2 JPS6152444B2 (en) 1986-11-13

Family

ID=15775939

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16354678A Granted JPS5587118A (en) 1978-11-25 1978-12-25 Focusing method which prevents change in angle of view

Country Status (1)

Country Link
JP (1) JPS5587118A (en)

Also Published As

Publication number Publication date
JPS6152444B2 (en) 1986-11-13

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