DE1073769B - Wide-angle photographic or cinematographic lens - Google Patents

Description

Photographic or cinematographic wide-angle lens The invention relates to a photographic or cinematographic wide-angle lens consisting of six elements standing in the air, three of which are unpackaged individual lenses and three are composed of two lenses of opposite refractive power, with one meniscus cemented from a positive and a negative lens element and the other five Is arranged upstream on the lens side with an air gap that is greater than 150 [, the focal length of the overall system. In the system part on the image side, two collecting members designed as individual lenses enclose two meniscuses of negative refractive power, of which the meniscus facing the image side is composed of two lenses of opposite refractive power and the meniscus facing the longer beam width is not cemented, to which four lens members a collective member cemented from two lenses with opposite refractive power is upstream.

With a wide-angle lens constructed in this way, there was a requirement with the greatest possible elimination of all image errors over an extensive image field to achieve an extremely long focal length with a short focal length in order to be certain To be able to meet installation conditions. Such are z. B. for use in single-lens reflex cameras given by the deflecting mirror for the viewfinder system.

With the invention, the demand made could largely be met are such that at an angle of view of about 80 ° by at least 10% greater focal length than the total focal length was to be achieved, compared to what known systems of this type mean a considerable increase in performance. Achieved this was achieved by such a distribution of the refractive powers within the system elements, that on each of the cemented surfaces in the lens facing the longer beam distance negative refractive power and an nd-value difference in the subsequent collecting link of more than 0.12 is present, and also the last in the overall system arranged meniscus-shaped converging lens made of optical glass with a larger na value than 1.72.

The new system is therefore because of the fulfillment of these and others Construction conditions both as a viewfinder and as a taking lens for two-eyed SLR cameras suitable for the purposes of wide-angle photography, where too in its capacity as an interchangeable lens, the requirement: compliance with the same Back focus as the basic lens could be met.

The following numerical example shows the design data of a system according to the invention with the relative aperture ratio of 1: 5.6 for the focal length f '= 100. In accordance with the drawing, the lens radii are denoted by r, the thicknesses and air gaps with d: Focal ratio 1: 5.6 f '= 100 s' = 116.30 nd vd y1 = + 106.02 L1 dl - 8.07 1.67270 32.2 I y2 = x L2 d2 = 2.24 1.52277 51.2 73 = + 32.29 d3 = 19.30 = air gap 7 4 = + 37.88 L3 d4 = 2.24 1.67786 55.3 II y5 = + 20.71 L4 d5 = 8.19 1.51895 57.3 195.93 d6 = 0.28 = air gap y7 = -i- 61.78 III L5 @ d7 = 5.83 1.61293 37.0 r8 = +2281.96 da = 1.75 = air gap VI L8 y9 = + 62.13 d, - 3.74 1.64,769 33.9 ylo = + 29.96 dlo = 6.78 = aperture space r11 = -40.18 L7 d11 = 2.24 1.63636 35.4 V r12 = + 40.42 L $ d12 = 10.46 1.67786 55.3 r13 = - 49.97 d13 = 0.23 = air gap 714 = - 74.00 VI L9 d14 = 5.75 1.74400 45.1 y15 = - 40.50 77.10 In the sense of the invention, the collecting members III and VI are designed as individual lenses and include two meniscuses IV and V of negative refractive power, of which the meniscus IV facing the longer beam width is also cemented and the meniscus V facing the image side consists of two lenses L, and La opposite Refractive power is composed. These objective parts III to VI are preceded by a collecting member II cemented from two lenses L3 and L4 of opposite refractive power and a meniscus I of negative refractive power with a large air gap on the side of the longer beam width, which is cemented from a positive and a negative lens element L1 and L2 .

There is a difference in the refractive index on the cemented surface y2 in the front lens element I. for the nd line of the spectrum of 0.15, at the cemented surface r5 in the following collector link II of 0.16, is therefore significantly larger on both cemented surfaces in the Sixine of the invention than 0.12. The meniscus-shaped converging lens arranged at the last point of the overall system consists made of an optical glass with a refractive index of 1.74 for the nd line thus also here the set condition for a system constructed according to the invention.

Claims (2)

PATENT CLAIMS: 1_ Photographic or cinematographic wide-angle lens with a long focal length that is greater than 90 ° / 9 of the focal length, consisting of six limbs standing in the air, three of which represent single lenses with urine cement and three are composed of two lenses each with opposite refractive powers, wherein a meniscus cemented from a positive and a negative lens element negative refractive power the other five members on the lens side with an air gap is upstream, which is greater than 15 ° / 9 of the focal length of the entire system, and in which two collective members designed as single lenses have two menisci include negative refractive power, of which the meniscus facing the image side It is uriverkittet which four image-side lenses are one of two lenses opposite refractive power cemented collecting member is arranged upstream, characterized by such a distribution of the refractive powers within the system members that on each of the cemented surfaces (y2) in the object facing the longer beam distance ective link (T) with negative refractive power and (y,) in the following collective link (II) there is an nj-value difference of more than 0.12, and also that of the latter Place of the overall system arranged meniscus-shaped converging lens (L9) made of optical Glass with an nd value greater than 1.72 is made. 2. An optical system of greater viewing angle performance according to claim 1, characterized by the following structural features, based on the focal length f '= 100: well y1 = + 106.02 I L1 y - @ dl = 8.07 1.67270 32.2 L2 y2 = 32 29. d2 2.24 1.52277 51.2 d3. = 19.30 air gap y4 - +. .37.88 II L3 y5 = + 20.71 d4 - 2'24 1.67786 55.3 L4 d5 = 8.19 1.51895 57.3 ys = + 195.93 d, = 0.28 air gap III L5 r ' + 61'78 d7 = 5.83 1.61293 37.0 ys = +2281.96 d8 1.75 air gap IV L, r, = + 62.13 d9 - 3.74 1.64,769 33.9 y19 - + 29.96 d19 = 6.78 aperture space r11 = -40.18 L ,, d11 = 2.24 1.63636 35.4 VL, y12 = + 40'42 d12 = 10.46 1.67786 55.3 y13 = - 49.97 d13 = 0.23 air gap y14 = - 74.00 VI L9 d14 = 5.75 1.74400 45.1 y15 = - 40.50 77.10, where the back focal length s' = 116.30: -Respected publications: German patent application 0 2269 IX / 42h (published on 18.3.1954); Swiss Patent No. 294 756.