DE1772285C - Achromatic super wide angle lens - Google Patents

Description

The Lirtinduiig refers to an 'achromatic Super wide angle subjective.

Such a lens, also known as a fisheye lens, with an angle of view of around 180 °, is in commonly assigned Japanese Patent Publication 438,664 described.

In contrast, according to the invention, an achromatic super wide-angle lens is to be made available that has a light intensity of up to F / 5.6 and an angle of view of about 220 to 270 ° and in which the chromatic aberration and other lens errors are very well corrected.

Wide-angle lenses with angles of view of up to 270 ° are known per se, but this is the case with a super-wide-angle lens with an image angle above 80 ° it is very difficult to correct the chromatic aberration and the image curvature. Will in particular If the angle of view is about 220 °, then the one generated in the strongly negative lens of the front part The aberration is considerably high, and especially the correction of the chromatic aberration becomes large difficult.

The invention is based on the object of overcoming these difficulties.

This is based on the following general design considerations:

The achromatic super wide angle! objective should show:

two or three zl r-scattering meniscus lenses, which are extremely curved towards the object side,

a screen,

a first doublet or triplet between the meniscus lenses and the diaphragm,

a second doublet, a converging lens and a 21insig cemented rear link behind the diaphragm, and a filter in front of the aperture

as well as the following requirements:

a) for the meniscus lenses is a glass with a refractive index greater than 1.57 and an Abbe number larger than 54 provided;

b) In the first doublet in front of the aperture, the glass of the positive lens should have an Abbe number less than 40 and the lens itself should have a focal length / ₊ that is less than five times the total system focal length /, and the glass of the negative lens should have an Abbe -Number greater than 50 and the lens itself have a focal length /, which is less than 5 / in terms of amount;

c) In the second doublet behind the diaphragm, the glass of the negative lens should be one Abbe number smaller than 35, the glass of the positive lens have an Abbe number greater than 35 and a refractive index at the d-line greater than 1.60; and Finally, the cement surface has a radius of curvature greater than 0.3 / but less than 3 /;

d) in the rear pillar, the radius of curvature of the cemented surface should be greater than 0.1 / but less than 5 /; the refractive index of the medium in front of the cement surface should be greater than that of the medium behind the cement surface; the positive lens should have an Abbe number greater than 45 and the negative lens an Abbe number less than 30.

The lens according to the invention has the im

ίο claim 1 or in claim 2 specified data.

A recorded according to the above data

Hautes achromatic super wide-angle lens is also suitable for color photography, with additional

the astigmatism in the peripheral image

zones, the correction of which was previously insufficient, is corrected very well. Furthermore, one obtains Sufficiently clear images even when the lens is used in conjunction with a 35mm camera where high magnifications in image

ao playback are required.

The objectives of the invention are described in the drawings. It shows

Fig. 1 the objective according to claim 1,

F i g. 2 shows the correction status of the lens

as Fig. 1,

F i g. 3 the objective according to claim 2,
F i g. 4 shows the state of correction of the objective according to FIG. 3.

In the case of the lens according to FIG. 1 are two where

according to FIG. 3 three diverging meniscus lenses Ll, L2 or Ll ', Ll and Ll are provided which are extremely curved towards the object side (to the left). Between these meniscus lenses and the diaphragm, a doublet (FIG. 2) or a triplet (FIG. 3) is provided which

is made up of lenses L3, L4 or L3 ', LA' and L4. Behind the diaphragm (to the right of this in the drawing) the second doublet L6, L1 is provided, followed by the further lens elements L8, L9 and L10. L 5 is an appropriately provided filter. The system fulfills the requirements mentioned at the beginning.

Conditions a), b) and d) enable correction of the lateral chromatic aberration over half the angle of view from 110 to 135 ° and result in very good image flattening. Will this If conditions are not met, it is difficult to correct these errors through the rear lenses. This condition is derived from the silkic aberration coefficients for given below the lens according to FIG. 2 can be seen. Condition b) has a detrimental effect on the correction the longitudinal chromatic aberration, the latter is therefore corrected out by condition c), whereby the detrimental effects of condition b) are compensated.

The remaining aberrations can be corrected by the rear lenses. The correction of the astigmatism and the compensation of the lateral chromatic aberration is done very well by the

Condition d).

If these conditions are not met, it is difficult to correct the astigmatism in the peripheral image areas. Below are the silky aberrations coefficients for / = 1 and the lens according to F i g. 2 reproduced, although these are not particularly suitable to reproduce the properties of the super wide-angle lens according to the invention.

I. 3
I / i 772 285
II / III / -IV / 0.0227 ϊ
IV / 4th
ν / 1 0.0003 0.0020 -0.0175 0.0542 0.3143 -0.0311 0.0165 0.0850 -0.1339 0.0709 3 0.0111 0.0217 -0.1639 0.0852 0.1671 4th -1.7782 0.3818 0.1803 -0.3497 0.0751 5 0.0413 0.0610 0.0027 0.0406 0.0601 6th 4.1173 -0.0747 -0.2252 0.0665 -0.0012 7th -1.6867 -0.4358 0.2277 -0.1864 -0.0481 8th 0.4959 0.2376 -0.2353 0.1139 0.0546 9 -0.5124 -0.2455 0.3295 -0.1176 -0.0 ', 4 10 0.6982 0.3392 -0.0878 0.1634 0.0794 11th -3.2596 -0.3761 -0.0055 -0.0523 -0.0060 12th -0.0106 0.0054 0.0897 0.0730 -0.0369 13th 0.0135 0.0264 0.0000 0.0306 0.0559 14th 0.0014 0.0227 -0.1678 0.1499 0.0002 15th -0.0655 0.0741 -0.0161 -0.0156 0.0177 16 -0.0207 -0.0129 0.0182 -0.0333 -0.0208 17th 1.9186 0.1320 0.0379 0.0643 0.0044 Σ 14.0656 0.1735 -0.0474 0.7301

Claims (2)

Patent claims: 1. Achromatic super wide-angle lens with two or three dispersing meniscus lenses that are extremely curved towards the lens side, a diaphragm, a first doublet or triplet between the meniscus lenses and the diaphragm, a second doublet, a converging lens and a 21-inch cemented background behind the diaphragm and a filter in front the aperture as well as the following default conditions: a) for the meniscus lenses is a glass with a refractive index greater than 1.57 and one Abbe-Zah! larger than 54 provided; b) In the first doublit in front of the aperture, the glass of the positive lens should have an Abbe number less than 40 and this lens should have a focal length f , which is less than five times the total system focal length /, and the glass of the negative lens should have an Abbe -Number greater than 50 and the lens itself a focal length /. the amount is less than 5 /; c) In the second doublet behind the diaphragm, the glass of the negative lens should have an Abbe number less than 35 and the glass of the positive lens have an Abbe number greater than 35 as well as P'nen refractive index at the d-line greater than 1.60, and finally the putty surface has a radius of curvature greater than 0.3 /, but less than 3 /; d) in the rear pillar, the radius of curvature of the cemented surface should be greater than 0.1 /, but smaller than * Sf ; the refractive index of the medium in front of the cement surface should be greater than that of the medium behind the cement surface; the positive lens should have an Abbe number greater than 45 and the negative lens an Abbe number less than 30, characterized by the following data: 88.722 / = io, F / 5.6, 2 ω = 220 1.0 ν = = 58.6 30.356 ^η ι ⁼ 1.61272 Ί = 89.627 d * - 4.5 n _t = 1.0 ν - = 60.3 ^r t = 14.301 1
ä, = ² 14.5 Ή = : 1.62041 ^Γ 3 = - 66.282 rf «= 3.9 "4 ⁼ = 1.0 V ^: = 70.3 ^r 4 ⁼ 17.127 3
rf, = 1 15.5 "5 ⁼ = 1.48848 V ■ = 26.0 ^Γ 5 ⁼ 59.586 4th
rfe = 1.3 "β = = 1.78470 ^Γ β = ce 8th
rf »= 5.8 «7 = = i, o V = 58.5 ^Γ 7 = OO rf, = 3.2 "β = = 1.51743 ^r s = - 3220.849 7th
rfe ⁼ 1.9 "» ⁼ = 1.0 V = 26.0 ^r t = 14.816 rf. = 6.4 = 1.78477 V = 45.0 ^Γ 10 = - 56.365 rf .. = 5.6 »11 ⁼ = 1.74372 ^Γ ιι ⁼ -305.981 rf »= 11.3 "li ⁼ = 1.0 V = 46.5 ^r l2 = - 28.988 11th
rfii = 0.2 »: S ^: = 1.76764 'IS = 64.417 IZ 4.8 M; . ^; = 1.0 V ■ = 26.0 ^Γ ιι = 22,224 Ii *
rf. «= 17.2 = 1.78485 V = 53.1 Ία -69.508 rfis ~ 2.6 "ie = 1.62230 'ie = you = 17.4 ^f 'l7 = 1.0 'l7 = "lR 2. Lens according to the preamble of claim 1, characterized by the following data: / = 10, F / 5.6, 2-,) = «I = _r = 204.583 rf. = 10.2 r, = 83.879 ^{! 2} _d = 43.0 r, = 112,709 * ³ rf, = 5.7 _Γι = 38.564 ^{s 4} rf. = 31.1 ι- = 113,858 ⁴ rf «= ⁴ ' ⁹ r, = 18.167 ^{s 6} rf. = 19.6 r = -84.202 rf. = 1.6 r _e = 21,757 .c rf. = ^{5 7 n} i = 1.51680
1 C \ ν = 64.2 "s =
«4 = 1.0
1.61272 ν = 58.2 "s = 1.0 »Β = 1.62041 V = 60.3 η- = 1.0 "s = 1.48848 V - 70.3 "β ⁼ 1.78470 V = 26.0 "in = 1.76764 V = 46.5 rf "= 1.6 '"_ d _n = 2.5» "- 1.51743 ν = 58.5 ^r "" ^ ä " - 8.2 B ₁ , = '..-- «Ο" · « ¹ Ζ, ₇ .2 »,. = ..78477 ν-26.0 r "- 18,822" "= 1,744" ν = 49.4 '»- - ⁷¹ - ⁶⁰⁴ , = 0.2»,. = '" ⁼ " ⁸ 3Γ ₅ ^; = ⁶ '· "- = ¹ - ⁷⁶⁷⁶⁴ ^ ⁴⁶ ' ⁵ r .. = - J0, ÖZ5 r - 81833 «Ή = ²¹ ' ^{9 n} « ^{= 1} ' ° ^Γιβ " ⁸¹ ' ⁸³³ = 3.3 n ₁₉ = 1.78485 ν = 26.0 I I JlViJ '" '19 "" r, ₀ = "21 = ^1Λ For this purpose ί sheet Zdc * iBniuu «in