DE1014752B - Photographic or cinematographic lens with a large field of view - Google Patents

Description

Photographic or cinematographic lens with a large field of view The invention relates to a large photographic or cinematographic lens Angle of view power, consisting of a collecting composed of four elements System part, of which in a known manner a biconcave lens between three collecting members is arranged so that two of the same face the side of the longer beam width and from a negative system consisting of two menisci of negative refractive power, that of the collecting system part with the known effect of an inverted telesystem is upstream.

Such a system is with sufficient light intensity and large picture angle performance according to its general structure to achieve an extremely long back focal length suitable to use it for special installation purposes, e.g. B. for use in conventional SLR cameras to make usable.

In the case of a taking lens, there is this basic construction the invention is that that located in front of the biconcave lens of the collecting system part The limb is designed as a positive meniscus lens with greater deflection, which its Hollow surface facing the biconcave lens, and made of a very low glass Refractive power exists, its refractive index for the yellow n-line of the spectrum is less than 1.50. This inventive measure is a leveling of the causes astigmatic image shells.

Furthermore, the new system is characterized by the fact that the biconcave lens in the collecting system part following collecting element facing the image plane two lenses are cemented, made of glasses with high refractive power - their refractive indices for the yellow n-line of the spectrum together are greater than 3.3 -exist and on of the cemented surface have a very small difference in the refractive index of less than 0.01. This further construction measure results in a reduction in the Komarest errors enables.

The new system still fulfills the basic condition s'> 1.25 f ', and the overall height 1 11 d is approximately equal to this size; the air gap between the negative system and the collecting system part is about a third of this Construction height.

The construction data of a lens according to the Invention listed, derived from the focal length f '= 100. The relative aperture this system is 1: 4, the angle of view is around 75 °.

The lenses of the two system elements are in accordance with the drawing I and II with L1 to L7, the radii of the lenses with r1 to y13 and the thicknesses and Air gaps labeled dl to d12. d4 is the large air gap between the two system parts I and II, d8 the diaphragm space.

The one located in the collecting system part II Numerical example f '= 100.00 s' = 130.36 y1 = + 101.14 nd va L1 dl = 4.94 1.6228 56.9 r2 = + 56.47 I d2 = 12.79 air gap 7, = -E- 146.22 L2 d3 = 4.80 1.6230 58.1 y4 - -1-- 65.26 d4 = 45.05 air gap y, = -f- 110.07 L3 d5 = 16.53 1.6261 39.1 r6 = -188.08 d6 = 0.53 air gap 51.35 L4 d7 = 6.80 1.4707 67.2 y8 = + 173.06 d8 = 15.97 air gap il r3 = -105.23 L5 de = 3.85 1.6990 30.1 ylo = -I- 56.09 dlo = 4.48 air gap r11 = + 219.09 L 6 d11 = 3.19 1.6727 32.2 y12 = -f- 141.28 L7 'd12 = 11.21 1.6779 55.3 y13 = - 55.60 d = 130.14 positive meniscus L4 has a strong deflection, with its hollow surface r $ facing the subsequent biconcave lens L5. It consists of a glass with the refractive index 1.47 for the yellow n-line of the spectrum, so it has a lower refractive power than 1.50 according to the claims.

The collecting member following the biconcave lens L5 in system part II is, according to the claim, made of two lenses L6 and L., such glasses cemented, their refractive indices for the yellow n-line of the spectrum are together greater than 3.3, where on the cemented surface r "there is a difference in the refractive index of less than 0.01.

The back focal length s' of the new system is 130.36, thus fulfilling the inventive condition s '> 1.25 f', where 12d is approximately equal to this size and also the air gap d4 between the two system parts I and II is approximately a third of this height is.

This means that all of the requirements for creating a system are of the invention met.

Claims (3)

PATENT CLAIMS: 1. Photographic or cinematographic lens large viewing angle performance, consisting of a system part made up of four elements, of which a biconcave lens is arranged between three collecting members so that two of them are turned towards the side of the longer beam width, and one of them Negative system consisting of two menisci of negative refractive power with the effect an inverted telesystem is arranged upstream, characterized in that the before the biconcave lens (L6) of the collecting system part II located member as a positive Meniscus lens (L4) is designed with strong deflection, which has its hollow surface (r $) facing the biconcave lens (L5), and made of a glass with a very low refractive power exists whose refractive index for the yellow n-line of the spectrum is less than 1.50. 2. Photographic or cinematographic lens according to claim 1, characterized in that that the one following the biconcave lens (L,) in system part II, faces the image plane The collecting member is cemented from two lenses (L, and L7), which are made from glasses with high Refractive power - their indices of refraction for the yellow n-line of the spectrum together are greater than 3.3 and consist of a very small difference in the refractive index on the cemented surface (r ") less than 0.01. 3. Photographic or cinematographic lens according to claims 1 and 2, characterized in that the back focal length of the system the condition s '> 1.25 f' is fulfilled and the overall height Z 1 d is approximately equal to this size and also the air gap (d4) between the negative system I and the collecting one System part II is about a third of this height.