RU2123713C1 - Wide-angle fast lens - Google Patents

Abstract

FIELD: moving picture equipment. SUBSTANCE: wide-angle fast lens has two components separated by aperture diaphragm. First component includes negative meniscus, biconvex lens, negative meniscus, biconvex lens, positive meniscus, two negative menisci, and biconvex lens positioned in succession. Second component consists of biconvex lens, biconcave lens, positive double-lens meniscus, and two biconvex lenses. Thirteen-component lens has the following technical data: relative aperture of 1:1.2, field of vision of 84 deg. , relation of S' to F' equal to 2.34, where S' is rear section of lens and F' is lens focal distance. EFFECT: increased aperture ratio and extended field of vision of lens with simultaneous enlargement of rear focal section. 1 tbl, 3 dwg

Description

 The invention relates to film technology and can be used in filming equipment, in particular for shooting films in the format S 16 (7.5 x 12.3 mm).

 A well-known lens of the company "Opton" F '= 8 mm with a relative aperture of 1: 2, which has high image quality, but this lens has insufficient aperture and, moreover, it is designed for the usual 16 mm format and does not provide the ability to shoot on the format S 16 due to insufficient field of view.

 A known lens according to the patent of Great Britain 14955077, cl. G 02 B 9/64, priority dated 12/18/1975, containing two components separated by an aperture diaphragm, the first of which is made in the form of a positive and two negative menisci facing concavity to the image, and a biconvex lens, the second component is made in the form of a biconvex lens , a biconcave lens, a double-glued positive meniscus convex to the image, and a biconvex lens.

 This lens has a small field of view (75), which does not allow shooting at S16 format, and its disadvantages are a low aperture ratio (1: 1.4), low image quality and insufficient rear focal length, which makes it impossible for small focal lengths lens distances to use it in modern filming machines with a mirror shutter.

 Thus, the invention is aimed at increasing the aperture and field of view of the lens while increasing the rear focal length with higher image quality.

 The technical result achieved by solving this problem is to increase the functionality of the lens, for example, shooting in rooms with low light and the ability to use the lens in almost all 16 mm movie cameras.

 The problem is solved due to the fact that seven elements are introduced into the well-known lens. A group of six lenses is installed in front of the first component, the first of which is the negative meniscus facing the concavity of the image, the absolute value of the relative optical power of which is not more than 0.13 and not less than 0.02 of the optical power of the entire lens, the second is a biconvex lens, relative the optical power of which is not more than 0.1 and not less than 0.01 of the optical power of the entire lens, the third is the negative meniscus facing the concavity to the image, the absolute value of the optical power of which is not more than 0.2 and not m it is 0.1 of the optical power of the entire lens, the fourth is a biconvex lens, the optical power of which is not more than 0.09 and not less than 0.005, the optical power of the entire lens and biconvex lens installed after the second component in front of the image plane, the relative optical power of which is not more than 0 , 25 and at least 0.15 of the optical power of the entire lens.

The invention is illustrated by the following drawings:
FIG. 1 is a schematic optical diagram of a lens;
FIG. 2 - graphs of the aberration of the lens;
FIG. 3 - graphs of the modulation transfer function of the lens.

 The proposed lens (Fig. 1) consists of components 1 and 2, separated by an aperture diaphragm 3. Component 1 contains a negative meniscus 4, a biconvex lens 5, a negative meniscus 6, a biconvex lens 7, a negative meniscus 8, two negative meniscus 9 and 10 and a biconvex lens 11.

Component 2 contains a biconvex lens 12, a biconvex lens 13, a positive biconvex meniscus 14 and two biconvex lenses 15 and 16. According to the proposed scheme, an Optar 1,2 / 8 lens (16 OKS 2-8-1) has been developed, which has the following technical characteristics:
Focal length, mm - 8
Back focal length, mm - 18.7
Relative aperture - 1: 1,2
The horizontal field of view, degree - 76
The diagonal angle of view, degrees - 84
The lens has a high level of aberration correction. Graphs of aberrations and MPFs characterizing the quality of the proposed lens are shown in FIG. 2 and 3.

 The design parameters of the proposed lens are shown in the table.

Literature
1. UK patent N 14955077, CL G 02 B 9/64, 1975.

 2. OPTON ARRIFLEX Lensos by catalog.

Claims (1)

 A fast wide-angle lens containing two components separated by an aperture diaphragm, the first of which is made in the form of a positive and two negative menisci facing concavity to the image, and a biconvex lens, the second component is made in the form of a biconvex lens, a biconcave lens, a double-glued positive meniscus inverted to the image, and a biconvex lens, characterized in that a group of lenses is installed in front of the first component, the first of which is a negative meniscus, image a concavity to the image, the absolute value of the optical power of which is not more than 0.13 and not less than 0.02 of the optical power of the entire lens, the second is a biconvex lens, the optical power of which is not more than 0.1 and not less than 0.01 of the total optical power the lens, the third is the negative meniscus, facing concavity to the image, the absolute value of the optical power of which is not more than 0.2 and not less than 0.01 of the optical power of the entire lens, and a biconvex lens, the optical power of which is not more than 0.1 and not less 0.05 opt Because of the total power of the entire lens, the second component is equipped with a biconvex lens, which is the last lens of the lens, the optical power of which is not more than 0.25 and not less than 0.15 of the optical power of the entire lens.

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