DE1151395B - Enlargement wide angle lens - Google Patents

Description

The subject of the invention is a wide-angle magnification lens, that of four meniscus-shaped lens elements separated from one another by air gaps consists, namely two meniscus-shaped, non-cemented lenses of positive refractive power, which the Include aperture, the aperture space delimiting surfaces of these members each other facing hollow sides, and from a meniscus-shaped front and rear phalanx of negative refractive power, each consisting of two lenses of opposite refractive power cemented to one another, whereby the lenses of these members facing the diaphragm are the scattering ones and have a higher dispersion than the lenses cemented with them and are mutually corresponding in the absolute amounts Radii of the glass-air surfaces by a maximum of 0.03 /, i.e. a maximum of 3% of the focal length of the lens differentiate.

It is known that triplet-type objectives were preferably used as enlargement objectives, which, however, only have a good and constant image quality for a small enlargement range and a relatively small angle of view and are sufficiently corrected only for a relatively small spectral range. Five-lens enlargement lenses in triplet variants have also become known which meet the requirement for good image quality in the usual enlargement range and the required spectral range. These enlarged objectives, which have become known, are able, for example, to ^{reproduce the negative format 24-36 mm 2} in an embodiment focal length of approximately 50 to 60 mm in the magnification range of approximately twice to twelve times magnification. In addition, a wide-angle magnifying lens of the Gaussian type has become known which, with a focal length of about 60 mm, is able to reproduce the 50 × 50 mm negative format in the range of 2 to 12 times magnification.

The invention seeks to create magnifying lenses whose field of view is expanded in this way is that ζ. B. with a corresponding focal length of about 60 mm, the negative format of 56 x 56 mm is reproduced in the entire magnification range from 2 to 12 times magnification. In addition, the image quality of the magnifying wide-angle lens according to the invention is so improved that that the gain in image sharpness achieved by modern shooting lenses also in magnification is maintained over the entire magnification range, with the error correction on one extended spectral range from about 400 to 720 ιημ

Applicant:
Agfa Aktiengesellschaft, Leverkusen

Dr. Christian Otzen, Grünwald near Munich,
has been named as the inventor

Wavelength extends so that it can be used equally for black and white enlargements and for color enlargements is made possible.

It is particularly advantageous in the objective according to the invention that the main points of the system close together, a property common to triplet-type and Triplet variants exist, but rarely occurs with magnifying lenses of the Gaussian type. When using an auto-focus enlarger with a magnifying lens of the triplet type or a triplet variant of a certain focal length, then that can Objective according to the invention with the same focal length can be used as an interchangeable lens, without the mechanical auto focus control or the distance between negative and Having to change the positive level.

The geometrical-optical correction in spherical, astigmatizer, comatic and, above all, chromatic Regard as well as the description has been very refined. It has also been found that the almost symmetrical structure of the negative outer members has a favorable effect on the astigmatic shell displacement affects when going through the magnification scale from twelve times to twice, so that the curvature of the field in the magnification range that is still mostly attached to asymmetrical lens types could be completely eliminated three or two times.

The invention is therefore based on the wide-angle lens type known for recording purposes, as at an objective type of a triplet variant as a magnification wide-angle objective not the refined astigmatic one and comatic correction is achievable over such a large angle of view and there with one Gaussian type does not have the small dimensions such as length, lens diameter of the outer links and the almost coherent main points are achievable.

In the case of the lenses described in numbers below, it has been possible to achieve wide-angle magnification

309 620/93

to provide objectives that have been remedied so far and evenly, that the image performance that the lenses have at full aperture is hardly increased by stopping down will. This success is all the more highly valued as it succeeded in refining the geometrical-optical design Correction, especially in chromatic terms, over the wide spectral range from 400 to 720 πΐμ in a good quality over the extraordinarily expanded field of view with a magnifying wide-angle lens to be carried out with coherent main levels.

The lenses listed below are specified for a focal length / = 1.0 and an aperture ratio of 1: 4.5. The radii are with R ₁ to i? ₁₀ , the axial lens thicknesses with d _t to d _e , the axial air gaps with Z ₁ to Z ₃ , the refractive indices of the glasses with Yi ₁ to n _R , their Abbe numbers with V ₁ to V ₀ . The refractive indices refer to the wavelength of 587.6 πΐμ. The construction elements are numbered consecutively, in the direction of the negative plane N to.

The drawing shows the section through lens I. The diaphragm is indicated by BB. The negative plane is marked with N, the positive plane with P.

Lens I

Magnification wide-angle lens 1: 4.5 lens focal length / = 1.0

lens

corrected for the enlargement interval 12 to 2 times

R ₁ = +0.28255

R ₉ = +10.30451

R ~ ₃ = +0,20152

# 4 = +0.40912

R ₅ = +0.81423

R ₆ = -0.54639

R ₇ = -0.26442

40

45

50

55

60

35

R ₈ = -0.19634 +0.28349 V ₁ ■ = 54.80 * 9 = -10.30451 + 20.62918 ^V 2 ^: = 47.04 ^R W ~~ -0.27214 + 0.20219 d _x = 0.09522 n _x = 1.69100 + 0.40920 ^v s' = 51.36 4 = 0.02683 M ₂ = 1.62374 + 0.81470 Z ₁ = 0.02087 -0.55670 "4 ⁼ = 50.93 4 = 0.06972 n ₃ = 1.55361 -0.26973 h = 0.07187 -0.19699 "s ⁼ = 33.88 ^ ₄ = 0.05415 M ₄ = 1.52310: -20.62918 "β = = 47.90 h = 0.01259 -0.27304 ^ ₅ = 0.02368 M ₅ = 1.64,769 1 1: 4.5 ^ ₆ = 0.10648 M ₆ = 1.71700 5 Objective II 12 to 2 times Wide-angle magnifying lens Lens focal length / = 1.0 KJUjCtLUV
corrected for the enlargement interval R ₁ = # 2 = R ₃ = R4 - Rr = R ^a = R ₇ = ^R l = ■

J ₁ = 0.09554
d ₂ = 0.02692
Z ₁ = 0.02094

d ₃ = 0.06580
Z ₂ = 0.07078

d _t = 0.05018
Z ₃ = 0.01263

d ₅ = 0.02376
d _e = 0.10684

H ₁ = 1.69100 n _t = 1.62374

n ₃ = 1.55115 n ₄ = 1.53172

n ₅ = 1.64,769 n ₆ = 1.71700

V ₁ = 54.80 v ₂ = 47.04

v ₃ = 49.61 V ₁ = 48.87

v ₅ = 33.88 v _R = 47.90

Claims (2)

Claim ε-1. Magnifying wide-angle lens consisting of four meniscus-shaped lens elements separated from one another by air gaps, namely two meniscus-shaped, non-cemented lenses of positive refractive power, which enclose the diaphragm, the surfaces of these elements delimiting the diaphragm space facing each other, and of a meniscus-shaped front and side Rear segment of negative refractive power, which consists of two lenses of opposite refractive power cemented to one another, whereby the lenses of these members facing the diaphragm are the diffusing ones and have a higher dispersion than the lenses cemented to them and differ in the absolute amounts of their corresponding radii of the glass -Air surfaces (A ₁ and R ₁₀ ; R ₃ and R ₈ ) differ by a maximum of 3% of the focal length of the lens, as characterized in that the refractive powers A n / R each by a maximum of ± 0.05 // and the lens thicknesses (i.e. ) and the air gaps (Z) each by a maximum of ± 0.02 / of the fol The values to be taken from the numerical example differ: R ₁ = + 0.28255-f
R ₂ = + 10.30451 · /
A ₃ = + 0.20152 · /
K ₄ = + 0.40912 · /
A ₅ = + 0.81423 · /
R _e = -0.54639 /
R ₇ = -0.26442 · /
R ₈ = -0.19634 · /
R ₉ = -10.30451 /
R ₁₀ = -0.27214 · / d _x = 0.09522 /
d ₂ = 0.02683 /
Z ₁ = 0.02087 / d ₃ = 0.06672 /
Z ₂ = 0.07187 / d _i = 0.05415 /
Z ₃ = 0.01259 / d _s = 0.02368 /
cZ "= 0.10648 · / U ₁ = 1.69100 n ₂ = 1.62374 n ₃ = 1.55361 n ₄ = 1.52310 n _r = 1.64,769 n _R = 1.71700 Δ n / R + 2.44558 // -0.00653 // -3.09518 // + 1.35317 // -0.67992 // -0.95737 // + 1.97829 // -3.29882 // -0.00673 // + 2.63467 // V ₁ = 54.80 v ₂ = 47.04 v _s = 51.36 v ₄ = 50.93 v ₅ = 33.88 v _e = 47.90 where R ₁ to R _{10 are} the radii, d ₁ to d _{e are} the axial lens thicknesses Z ₁ to Z _{3 are} the axial air distances in units of the lens focal length / and the refractive indices of the glasses for the wavelength of 587.6 ΐημ with n _x to n _R and their Abbe numbers are indicated by V ₁ to v _R. 2. Wide-angle magnification lens according to claim 1, characterized by the following design data: JnAR = + 0.28349 · / -! - 2.43748 // 5 = -20.62918 · / -0.00326 // = + 0.20219 · / -3.08492 // = + 0.40920 · / + 1.34690 // = + 0.81470 / -0.67651 // = -0.55670 / -0.95513 // ίο = -0.26973 · / +1.97130 // = -0.19699 · / -3.28793 // = -20.62918 · / -0.00336 // = -0.27304 · / + 2.62599 // d ₁ = 0.09554 / d _a = 0.02692 / C ₁ = 0.02094 / d ₃ = 0.06580 / I ₂ = 0.07078 ■ / d _i = 0.05018 / Aj. = 0.01263 / d ₅ = 0.02376 / d _s = 0.10684 / Considered publications: Austrian patent specification no. 201 313. ⁿ -2 Il Il , 69100
, 62374 "2 = 54.8C
= 47.04 n _s = 1, 55115 V ₃ = 49.61 «4 - 1 53172 = 48.87 ⁿ 5
«6 Ij
= 1, 64769
71700 ^V 5 = 33.88
= 47.90 1 sheet of drawings © 309 620/93 7.