SU1525654A1 - Mirror lens - Google Patents

Abstract

The invention relates to optical instrumentation and can be used in photographic optics. The purpose of the invention is to reduce the length, increase the relative value and image quality for a minimum focal length value. The change in focal length from 35.7 to 68.6 mm is carried out by simultaneously moving the first component from lenses 1-4 in a non-linear manner and the second component from lenses 5-9 in a linear manner. The relative aperture is from 1: 3.2 to 1: 4.5. 3 il.

Description

(L

315

The invention relates to optical-i-instrumentation, namely, to photographic lenses, and can be used in cameras of the Zenith type.

I The purpose of the invention is to reduce the length, increase the relative aperture and image quality for a minimum focal length.

Fig. 1 shows the principal optical scheme of the proposed lens; Fig. 2 is a plot of modulation transfer coefficient versus spatial frequency for a focusing distance of 35 $ 7 mm in the center of the field (y 0); in FIG. 3, the same for image edge (mm).

The lens consists of two components. The first component contains a positive double convex lens 1, an erectative meniscus 2 facing zagnostyu to the image, a negative meniscus 3, obshchy, concavity of the image, a positive meniscus protruding to the object. The second component is made of a positive two-convex lens 5, a positive meniscus 6, convex to the object, a negative color of the co-bent lens 7s of the negative meniscus 8 facing the concavity to the image, and a positive two-convex lens 9. I The lens works as follows | ,

 The change of the focal distance is accomplished by the interconnected re-displacement of the first component (1 k lens) according to a non-linear law and the second: the component (lenses 5-9) according to a linear law.

The lens is focused at a distance by moving the first component (lenses 1-4) toward the object, with the maximum amount of movement of the first component being 5.27 mm for a distance of 0.8 m.

For f 35, mm it is possible (screening at a distance of 0.3 m by moving the second component by 10.2 m in the direction of the object.

2.9

mm

Performing the lens according to the proposed scheme allows to obtain a lens with the following characteristics;

Focal distance 35., 65 mm Angle of view 61 ° 23: 3 27 Relative aperture I: 3s2-1t, 5 Lens length 127.87: 117.03 mm (Zd + s, -), 7 Cx Maximum light diameter Meridional image curvature (mm) Sagittal image curvature (at 19 mm) Distortion (at 21.6 mm) Spherical longitudinal (over the zone) Coma aberration (for

-0.355: -0.307 mm

-0.191: -0.5 mm 1.57

19 mm)

0.006: -0.010 mm -0.010: 0.0135 mm

Claims (1)

Invention Formula A pancratic lens containing two components that are interchangeably mounted along the optical axis, the first component containing four lenses, the first of which is positive, the second and three are negative menisci facing inward concavity to the image, and the fourth outward positive in meniscus facing in concavity to the image, the second component contains five lenses, the first of which is positive, the second is the positive meniscus facing the concavity of the image, the third is negative, the fourth is the meniscus, the fifth is positive, characterized in that, in order to reduce the length, increase the relative aperture and image quality for a minimum focal length, in the first component the first lens is made two-convex, in the second component the fourth lens is made in the form of a negative meniscus with concavity facing the image, and the second is in the form of a double-convex lens. w th 30 0 50 60 2  // U - / th 30 0 50 60 Schig.3