SU1377809A1 - Photographic zoom lens - Google Patents

Abstract

The invention relates to optical instrumentation and allows to increase the magnification of the scale, reduce the size and weight of the device. The component 1 of the lens after the negative meniscus (M) 5 contains a double lens lens (L) 6 and convex facing the object positive M 7. The fixed component 2 includes negative M 17 and glued two convex L 18 with double bent L 19 and negative M 20 with a positive M 21. Before component 3, made of two-convex L 8 and 9 negative I 10, an aperture diaphragm 16 is rigidly connected to it. A two-convex L 11, double-curved L 12, positive M 13 and scandal Negative M 14 with two co-convex 15 minutes to form component A 4 fixedly coupled to the component 1, and are moved with the same speed-, changed the focal length of the lens. Image plane immobility is provided by moving the component 3 with the diaphragm 16. The lens for SLR cameras with a frame format of mm has a 5.7-fold zoom ratio, 1 slug. (L

Description

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The invention relates to optical instrumentation, namely to lenses with variable focal distance, intended for use in both amateur and procession photography.

The purpose of the invention is to increase the magnification of the scale, reducing the size and weight.

The drawing shows the optical scheme of the proposed photographic lens with a variable focal length.

The scheme consists of 16 lenses, combined in four components 1-4. The first component is made of a negative meniscus 5, a double-contracted 6 and a positive meniscus 7, the third consists of two two convex 8 and 9 lenses and a negative meniscus 10, the fourth component consists of two double convex 11, a double-curved 12 lenses, a positive meniscus 13 and glued negative meniscus 14 and 15 double-convex lenses mounted for movement along the optical axis.

Moreover, the first and fourth components have similar values of optical forces, are rigidly connected to each other and move with the same speed, changing the focal distance of the lens. The movement of the third component ensures the immobility of the image plane. The aperture diaphragm 16 is placed in front of the third component at a distance of 0.78 mm, is rigidly connected with it and moves at the same speed. The fixed second component of negative optical power consists of a negative meniscus 17, glued two double convex 18 and two double bent 19 lenses and a glued negative 20 and positive 21 menisci. In the position when the first component is in the extreme right position, the lens has the smallest focal distance of 35 mm. With a maximum extension of the first component towards the object, the lens has the greatest focal distance equal to 200 mm.

and-

1377809 2

135 mm - with a contrast ratio of K 1 at

full relative aperture for three focal lengths f 35 mm, f 74 mm, f 200 mm in the center of the field

mm,

not less than 50 mm, on the edge of the floor (at 19.0 mm) not less than 30 mm H

The positive (technical and economic effect of the invention is that a variable focal length lens for SLR cameras with a frame format of 24x36 mm has a 5.7-fold zoom ratio and a reduced size and weight with high image quality.

Claims (1)

20 claims five A photographic lens with a variable focal distance, comprising four components, of which the first, third, and fourth are positive and mounted for movement along the optical axis, and the second is fixed, the first component includes a negative meniscus facing concavity to the image, and the fourth consists of two two convex lenses, the second of which are glued together from a negative meniscus and a double convex lens, characterized in that, in order to increase the magnification of the zoom, to reduce the envelope in the mass, in the first, positive, component after the meniscus, a two-co-convex lens and a positive meniscus convex to the object are introduced, the second, negative, component consists of a negative meniscus convex to the object, and two two-glued lenses, the first of which consists of double-dome and double-concave lenses, and the second one - of double-concave lenses and a positive meniscus, the third positive component is made of two double convex lenses and a negative meniscus convex to iu, and in the fourth component, bicocoins are introduced between the two convex lenses five 0 five 0 The resolution of the lens is a chickpea lens and a positive meniscus. on photographic material KN-1 with resolving convex to the image VNIIPI Order 869/43 Circulation 533 Random polygons pr-tie, Uzhgorod, st. Project, 4 convex to the image. Subscription