DE2426213C3 - Wide angle lens - Google Patents

Description

The invention relates to wide-angle lenses, in particular for aerial photography consisting of at least a raised meniscus on the object side with negative refractive power, one through a clear air gap Separate lens group with positive refractive power in front of the diaphragm and one also with positive refractive power Refractive power equipped lens group behind the diaphragm, with a concave positive on the object side Meniscus is provided as the first lens element of the positive lens group in front of the diaphragm.

The requirement for wide-angle lenses for aerial photography is that large image formats should be distortion-free to be filled out. They should also have the largest possible angle of view, good image sharpness and have a high resolution. Provide the best correction options for this purpose According to previous knowledge, wide-angle lenses that are constructed almost symmetrically to the aperture, positive members on both sides of the diaphragm and negative members at a clear distance therefrom on both sides Menisci are arranged. What is striking about all known wide-angle lenses for aerial photography is that that the front surfaces of all lens elements (not cemented or cemented) in front of the diaphragm to the object curved towards and correspondingly the rear surfaces of all lens elements curved towards the image behind the diaphragm are. The aperture ratios of these lenses are approximately 1: 5 at angles of view of approximately 90 °. at Using the previous types results in an increase in the aperture ratio that is too great chromatic variation of astigmatism and coma.

From DE-OS 23 28 558 a wide-angle lens with a large relative aperture and angles of view up to about 70 ° known. Following the front lens, this objective contains a meniscus which is hollow on the object side and which is suitable for the correction of the image errors with a wide-angle lens of the structure described above is very favorable affects.

The object of the invention was to create a wide-angle lens that is suitable for large image formats Improved state of correction achieved, which comes close to the usual with 35mm lenses. In particular shall be the zone of the chromatic difference in magnification as well as the chromatic difference of the astigmatism and the coma will be largely eliminated. The aperture ratio should be at least I: 4 and the angle of view must be greater than 90 °.

This task is achieved by designing the wide-angle lens of the type mentioned at the outset according to a the data tables listed in the characteristics of the present claims 1 to 3, modifiable within limits solved.

The F i g. 1 schematically shows an axial section of the objectives according to the invention and in FIGS. 2 to 4 the correction curves of the objectives according to the invention described in the tables are shown.

The correction curves show the transverse aberrations at different image heights y ' in the Gaussian image plane, which are plotted over the aperture of the objectives. The solid curves relate in the usual way of representation to the main sagittal section, while the dashed curves relate to the meridional section for the Fraunhofer line E (A = 546 nm).

Hicr / u 4 sheets of drawings

Claims (2)

Patent claims: 1. Wide-angle lens, especially for aerial photography, consisting of at least one object-side raised meniscus of negative refractive power, one by a clear air gap from it separate lens group with positive refractive power in front of the diaphragm and one also with positive refractive power Refractive power equipped lens group behind the diaphragm, with a concave positive on the object side Meniscus as the first lens segment of the positive Table 1 Lens group is provided in front of the diaphragm, characterized in that its design data agree with the design data given below insofar as the area part coefficients according to Seidel depend on the corresponding Seidel coefficients by about 10% and the sums of the Seidel coefficients from the corresponding sums differ by around 1%: Focal length : / = 100 radius 123.73 Distance to
w * tt * fin C t O η Refractive index Abbe number Angle of view: ± 46 ° 66.20 iiticnsicn
Lens surface Image circle diameter: 208 mm (rj -128.02 M. (nc) fVej) Focal ratio: 1: 2.8 -59.10 7.71 1.58482 40.58 area
rVlr - 143.61 85.17 - - ΓΝΓ. 71.27 23.96 1.64,504 59.85 (0 -239.26 5.14 1.64418 34.36 1 -10 369.07 3.01 - - 2 'Cover) 35.39 1.73940 41.32 3 -44.01 9.25 1.76167 27.37 4th - 52.83 6.81 - - 5 -837.83 19.14 - - 6th - 38.59 8.94 1.57047 42.56 7th -95.74 0.26 - 8th -44.31 15.67 1.69401 54.48 9 -88.51 3.85 1.79180 25.87 10 18.54 - 11th 4.37 1.57366 50.58 12th 52.47 13th 14th 15th 16 2. Wide-angle lens, in particular for aerial photography, consisting of at least one object-side raised meniscus of negative refractive power, one by a clear air gap from it separate lens group with positive refractive power in front of the diaphragm and one also with positive refractive power Refractive power equipped lens group behind the diaphragm, with a concave positive on the object side Meniscus as the first lens segment of the positive Lens group is provided in front of the diaphragm, characterized in that its design data with the design data given below in so far as the area sub-coefficients according to Seidel differ from the corresponding Seidel coefficients by about 10% and the sums of the Seidel coefficients from the corresponding The sums differ by around 1%: Table 2 Focal length: / = 100
Angle of view: ± 48.5 "
Image circle diameter: 226 mm
Opening ratio: 1: 3.4 Absland for
next
Lens surface Refractive index
(lh :,) Abbe number
(V,:,) Make radius
No
U) Uh) 7.86
88.44 1.58565 46.17 I 118.86
2 66.00 continuation radius 24 26 213 Meniscus of negative refractive power, one also with more positive more concave on the object side ± 46 ° radius 135.55 more positive 4th Refractive index '\ hbe - / .; ihl by about 10% and the Abbe number area clear air distance from it Refractive power-equipped lens group behind the Meniscus as the first lens element of the Image circle diameter: 208 mm 65.42 positive Sums of the Seidel coefficients from the corresp No. separate lens group of positive refractive power before 30 Aperture, being a Table 3 Focal ratio: I: 4 (n) -140.05 corresponding sums of the order of magnitude (Vc,) 3 Oh) Abscind to the aperture and area
Mr - 69.97 (nc) (Vc) Deviate 1%: 49.07 O) -129.18 next Focal length: / "= 100 INr. -167.22 1.64129 55.15 - 3 -65.20 l.inscnfläc Angle of view: 0) 75.37 1.64418 34.36 55.15 A. -153.80 Uh) 1 -104.12 - - 34.36 5 74.94 22.70 2 -973.90 Distance to 1.73940 41.32 - 6th -99.14 6.98 3 (Cover) next
Lens surface 1.76167 27.37 41.32 7th -852.04 4.56 4th - 38.53 (au - - Refractive index 27.37 8th (Cover) 40.58 5 -44.43 7.69 - - - 9 - 38.54 9.08 6th -430.37 78.76 1.57047 42.56 (nc) - 10 -44.46 6.98 7th - 32.38 16.28 - - 1.57240 42.56 11th -460.50 17.81 8th -91.89 13.46 1.68637 44.23 - - 12th -36.20 5.92 9 -48.53 4.49 1.79180 25 ° 7 1.64129 40.75 13th -94.64 0.17 10 - 104.80 August 34 - - 1.6441P- 25.87 ! 4 -47.63 14.30 11th 15.50 1.56605 60.55 - - 15th -108.97 4.37 12th 6.98 - - 1.73940 46.17 16 3. Wide angle lens especially for 29.93 13th 17.20 “Inner group in front of the Aperture is provided, 1.76167 4.37 14th 5.90 characterized, that its construction - 41.76 15th 0.19 data with the following specified construct - Aerial view 16 14.35 tion data match insofar as the areas 1.57047 photography consisting of at least one object 4.49 partial coefficients according to Seidel of the correspond - raised on both sides 34.46 the Seidel coefficient 1.70587 one by one 4.49 1.79180 43.24 - 1.58565