SU1282045A1 - Zoom lens - Google Patents

Abstract

The invention relates to optical instrumentation and can be used in reflex cameras of the Zenith type. In order to increase the field of view and expand the range of change in the focal distance in the second lens group, after a double-curved lens 7, made of glass with a refractive index of 1.55-1.7, a negative meniscus B, convex to the image, was installed. The positive lenses 5, 9, and 10, made double-convex, and the positive meniscus 6 are made of glass with a refractive index in the range of 1.45-1.6. The lens is focused on the final shooting distance by moving towards the object of the first lens group, including positive I and negative 2 menisci, convex to the object, negative lens 3 and convex to the object positive meniscus 4. Changing the focal length of the lens is made by moving along the optical axis of the first and second lens groups. The range of change of the focal length of the lens 25-45 mm when changing the relative aperture from 1: 2.8 to 1: 3.5. The field of view with a minimum focal distance is 83 °. 5 ill., 1 tab. (L

Description

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The invention relates to optical systems, in particular, to panoramic wide-angle photographic lenses, and can be used in reflex cameras such as Zenith,

The purpose of the invention is to increase the field of view and expand the range of change of the focal distance. Figure 1 shows the optical scheme of the lens, figures 2 and 3 show the graphs of the frequency-contrast characteristics (MFR) with a focal length of 25.4 mm for the center of the field () and edge of the field of view of Su 19 mm) corresponding to BeHHo .J in Figures 4 and 5 are the same, with a focal length of 44.6 mm for the center (y 0) and field edge (y 19 mm), respectively. I

The principal optical scheme of the pancritical lens (Fig. 1) is made of two groups of lenses, the first

of which consists of a sequence of 29 ° 42 with a corrected single-curvature along the beam, 25 ”relative curvature relative to the distortion J positive 1 and negative 2 meniscus convex to the object, a double-bent negative lens 3 and a positive meniscus 4 convex to the prediction. The second group is made of consecutively placed single double-convex lenses 5, positive meniscus 6, convex

The proposed lens replaces all four lenses, while the image quality is superior.

At a focal length of 25.4 mm, the longitudinal spherical aberration for the main wavelength (line e) does not exceed 0.31 mm, the secondary spectrum is 0.25 mm in the spectrum from the g line to the c line, astigmatism is not more than 0.29 mm long angles up to 37 ° 42 with corrected curvature, chromaticity increase of not more than 0.07 mm, relative distortion 3.%, the maximum value of aberrations of wide beams in the meridional and sagittal plane x is 0.085 mm.

At a focal length of 33.6 mm, the longitudinal spherical aberration does not exceed 0.314 mm, the secondary spectrum is 0.28 mm, astigmatism is not more than 0.19 mm

si 0.98%. the maximum aberration value of wide beams is 0.12 mm,

With a focal length of 44.6 mm, the longitudinal spherical aberration does not exceed 0.47 mm, the secondary spectrum is less than 0.09 mm, the astigmatism is no more than 0.31 mm for angles up to 23 with corrected 20

to an object that has a double-concave negative curvature, chromaticism of an enlarged lens 7, a negative meniscus 8 that is convex to the image, two convex positive lenses 9 and 10.

The change in focal distance is due to the interrelated movement along the optical axis of the first and second components. Focusing the lens on the final distance40

not more than 0.017 mm, relative distortion not more than 0.14%, the maximum amount of aberrations of wide beams is 0.061 mm.

Formula of Invention

A pancreatic lens containing two groups of single lenses, the shooting is carried out by means of repositioning with the possibility of moving

Place the first component of the lens towards the object.

The lens has a focal length range from 25 to 43 mm, with the relative aperture Q varying from 1: 2.8 to 1: 3.5. The field of view with a minimum focal length is 83.

Such characteristics of a pancritical lens allow it to be used to replace four lenses with constant focal length, relative aperture (1: n), focal distance (f) and photographic-optical axis, the first of which consists of positive and negative meniscuses with convexity to the object, a negative lens and a positive meniscus convex to the object, the second group contains a two-convex lens, a positive meniscus convex to the object, a double lens A dual lens and two positive lenses, distinguished by the fact that, in order to increase the field of view and broaden the range of the change in focal length, the resolution is shown in the table.

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which

   29 ° 42 when corrected- 5 „„ curvature, relative distor-Jo

The proposed lens replaces all four lenses, while the image quality is superior.

At a focal length of 25.4 mm, the longitudinal spherical aberration for the main wavelength (line e) does not exceed 0.31 mm, the secondary spectrum is 0.25 mm in the spectrum from the g line to the c line, astigmatism is not more than 0.29 mm long angles up to 37 ° 42 with corrected curvature, chromaticity increase of not more than 0.07 mm, relative distortion 3.%, the maximum value of aberrations of wide beams in the meridional and sagittal plane x is 0.085 mm.

At a focal length of 33.6 mm, the longitudinal spherical aberration does not exceed 0.314 mm, the secondary spectrum is 0.28 mm, astigmatism is not more than 0.19 mm

0

   29 ° 42 when corrected - „„ to curvature, relative distortion-J

si 0.98%. the maximum aberration value of wide beams is 0.12 mm,

At a focal length of 44.6 mm, the longitudinal spherical aberration does not exceed 0.47 mm, the secondary spectrum is less than 0.09 mm, the astigmatism is no more than 0.31 mm for angles up to 23 with corrected curvature, the chromatism increases

not more than 0.017 mm, relative distortion not more than 0.14%, the maximum amount of aberrations of wide beams is 0.061 mm.

Formula of Invention

A pancreatic lens containing two groups of single lenses, the set of the optical axis, the first of which consists of positive and negative menisci, convex to an object, a negative lens and a positive meniscus convex to an object, the second group contains a two-convex lens, a positive meniscus that faces a convexity to the object, a double-curved lens and two positive lenses, characterized in that, in order to increase the field of view and expand the range of change of the focal length One hundred PIAs, in the second group of lenses between the double-bent and positive lenses, a negative meniscus is set that faces the image convex, the positive lenses are double-convex, while two are convex.

World-14

World-10

World-24

Industar-50 Offered

lens

About 10 20 30 0 50 60

Figg

g

the lenses and the positive meniscus of the second group are made of glass with a refractive index of n within 1.45-1.6, and the double-curved lens is made of glass with a refractive index of n within 1.55-1.7.

24 28 35 50

25-45

45/20 40/20 40/21 45/17

45/26

N

Lin mm

y / y

H

din mm

Fig.Z

before

to 20 ЪО ftO 50 60

Figm

W 20 30 O 50 60

FIG. five

N

ling mm

N

li mm

Claims (1)

Claim A panoramic lens containing two groups of single lenses • mounted with the ability to move along the optical axis, the first of which consists of a positive and negative meniscus convex to the object, a negative lens and a positive meniscus convex to the object, the second group contains a biconvex lens , a positive meniscus convex to the object, whom the lens allows to use it to replace four lenses with a constant focal length, relative aperture (1: p), focal length (f) and a photographic 55 biconcave lens and two positive lenses, characterized in that, in order to increase the angle of field of view and expand the range of the focal length 1282045 4, in the second group of lenses between the biconcave and positive lenses there is a negative meniscus convex to the image, the positive lenses are biconvex, while the biconvex lenses and the positive meniscus of the second group are made of glass with a refractive index n _f within the range of 1.45- 1.6, and a biconcave lens made of glass with a refractive index n _g in the range of 1.55 - 1.7. Title Number of comp./ lenses 1 I | eleven eleven 1 Σ H> 1 2 - 1 eleven eleven eleven eleven eleven R, lin / mm center / edge World-14 7/8 1: 3,5 24 45/20 World 10 7/8 1: 3,5 28 40/20 World 24 7/8 1: 2 35 40/21 Industar-50 3/4 1: 3,5 fifty 45/17 Proposed lens 10:10 1: 2,8 25-45 45/26 3,5 lin mm