SU34783A1 - Photographic lens - Google Patents

Description

The subject matter of the proposed invention (a lot of the invention consists of a photographic lens consisting of five lenses-four. Collecting and one diffusing, which are arranged in such a way that the three collecting lenses separated by air gaps are located in front of the diffusing lens and are separated the collective lens is placed behind the diffusing lens and is also separated from it by an air gap.

There are photographic systems that, with a relative luminosity of f: 1.5, have good spherical and astigmatic correction. However, their spherical zonal errors are already so significant that it is out of the question to further increase the luminosity without degrading the image quality. According to the present invention, three collective meniscus are placed in front of a diffusing lens to reduce spherical zonal errors. With this arrangement, achieving a good coma and astigmatic correction depends on the particular shape of the diffusing lens.

In order to obtain a good coma and astigmatic correction for the whole field of view, i.e. for the beam of rays incident at different angles of inclination to the axis, the first surface, i.e. the surface of the diffusing lens following the front meniscuses Well-known systems of this kind.

With such a convex surface, the angles of refraction can be made, taking into account other refractive surfaces, less than that of the concave surface. Giving such a shape thus makes it possible to avoid a significant difference in the angles of refraction of obliquely incident beams and provides good coma and astigmatic cremation for the entire field of view.

In conjunction with a highly refractive flint, B5-1.80, the overall effect of a convex diffuse lens is obtained large enough to balance the highly collecting action of the collective meniscus.

The lens placed behind the lens diffuser doubles the lens cap and eliminates small coma and astigmatic residual errors.

The proposed system has a coma and astigmatic correction to the angle of view from the subject of the survey at 36 °.

Zonal errors parallel to the axis of the beam with the height of the fall

"Vfo, 5 is 0.195 mm for the proposed focal length / 100.

Here, the edge beam redirection is 1.2 mm.

For comparison, it is possible to take, for example, a spherical error corrected, according to German patent No. 461083, of a multi-lens lens of type /: 2, which, when corrected to 1.1 mm, has a spherical zone error of 0.8 mm. Achromatism is achieved with the help of flint, the refractive index of which is 1.78 or 1.8 for the D line, and 26.5, With less luminosity to /: 1.5 achromatism, it can be achieved already with flint “1.65 for

.line D and at v 33.8.

FIG. 1 shows a five-cylinder system with a focal distance relative aperture / :.

/-50

di 8.1

d, 0.25

d. 5.6

di 0.25

H5 10.3

,eight

d, 1,4

d, 12.0 d, - 8.0

Glass grades for line D and v value.

58.5

Inza. I

1.613 58.5 1.613

"P

.III 1,613 58.5

.IV 1.778 26.5 58.5

.V 1,613

Spherical and astigmatic correction are presented in FIG. 2 and 3 to scale.

The subject matter of the invention.

A photographic lens consisting of five separate lenses with air gaps between them, of which the first three lenses are meniscus-like collecting with convex surfaces facing the incident ray of light, the fourth lens is a diffusive and the second is a two-convex, differing in that, in order to obtain greater luminosity and better correlation to whom and astigmatism, the front surface of the scattering surface is directed towards the incident light beam. Li lens is made convex.

Shigz

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