DE1797434C3

DE1797434C3 - Photographic lens with rear aperture

Info

Publication number: DE1797434C3
Application number: DE19681797434
Authority: DE
Inventors: Joachim Dipl.-Phys. 3300 Braunschweig; Behrens Heinrich 7923 Königsbronn Eggert
Original assignee: Rollei Werke Franke und Heidecke GmbH and Co KG
Current assignee: Rollei Werke Franke und Heidecke GmbH and Co KG
Priority date: 1968-06-14
Filing date: 1968-09-27
Publication date: 1977-04-07

Description

Formelmäßig lauten diese BedingungenIn terms of formula, these conditions are

a) 1,0 - /> R₁ + R₁ > 0,6 · /a) 1.0 - /> R ₁ + R ₁ > 0.6 /

b) 0 < R₁ - R₁ < 0,15 · /b) 0 < R ₁ - R ₁ < 0.15 /

c) 1,10 < A₁': R₂ < 2,10 · /c) 1.10 <A ₁ ': R ₂ < 2.10 · /

d) 0,05 ■f<d₁< 0,20 · /d) 0.05 ■ f <d ₁ < 0.20 /

e) 2,5 Φ < ψ < 4,0 0e) 2.5 Φ <ψ <4.0 0

Die Bezeichnungen sind im übrigen in Übereinstimmung mit den F i g. 1 und 2 der Zeichnung gewählt. The designations are otherwise in accordance with FIGS. 1 and 2 of the drawing were selected.

F i g. 1 zeigt die Bauform nach den Ansprüchen 1 und 2, bei welcher der blendennahe Meniskus als Doublet aus zwei Linsen entgegengesetzten Stärkevorzeichens aufgebaut ist und dem auf der Seite der längeren konjugierten eine einzelne Meniskuslinse vorgeschaltet ist;F i g. 1 shows the design according to claims 1 and 2, in which the meniscus close to the glare as Doublet is made up of two lenses of opposite strength sign and that on the side of the longer conjugated a single meniscus lens precedes;

F i g. 2 zeigt die Bauform, bei der der längeren Konjugierten zugewandte Meniskus au5 zwei Linsen entgegengesetzten Stärkevorzeichen«, ausgeführt ist.F i g. 2 shows the design in which the meniscus facing the longer conjugate has two lenses opposite strength sign «.

Die Krümmungsradien R sowie die längs der optischen Ac'ise gemessenen Linsendicken d und Luftabstände α sind in Lichtdurchtrittsrichtung fortlaufend numeriert. Das im meniskenförmigen Doublet eingeschlossene Nachbarflächenpaar ist mit R_x bezeichnet.The radii of curvature R as well as the lens thicknesses d and air gaps α measured along the optical axis are numbered consecutively in the direction of light passage. The pair of neighboring surfaces enclosed in the meniscus-shaped doublet is denoted by R _x.

Die verwendeten Gläser sind durch die Brechzahlen der gelben </-Linie des Helium-Spektrums und ihre Farbenzerstreuung durch die Abbeschen v-Werte charakterisiert. Die Hinterblende ist mit B und ihr Abstand von der rückseitigen Fläche A₃' mit b bezeichnet. Die Längenangaben beziehen sich auf die Einheitsbrennweite von / = 100 mm, entsprechend einer Äquivalentbrechkraft 0 = 10,0 dptr.The glasses used are characterized by the refractive indices of the yellow </ - line of the helium spectrum and their color dispersion by the Abbe v-values. The rear panel is denoted by B and its distance from the rear surface A ₃ ' is denoted by b. The length specifications refer to the standard focal length of / = 100 mm, corresponding to an equivalent refractive power of 0 = 10.0 dptr.

Die Objektive gemäß Erfindung haben ein nutzbares Gesichtsfeld von etwa 35° bis 50°. Durch die Verlagerung des Blendenortes hinter das Gesamt-The objectives according to the invention have a usable field of view of approximately 35 ° to 50 °. Through the Relocation of the aperture behind the overall

objektiv werden insbesondere hinsichtlich Blenden- und Verschlußsteuerung dem Konstrukteur alle wünschenswerten Freiheiten zur Verfugung gestellt, so daß sich diese Objektive in besonderem Maße für Kameras mit Belichtungsregelung einsetzen lassen.Objectively, in particular with regard to diaphragm and shutter control, all are desirable to the designer Freedoms are made available so that these lenses are particularly useful for cameras let use with exposure control.

Trotz des einfachen Aufbaus der Objektive, welches zudem nur sphärische Flächen enthält, wird mit einfachsten technischen Mitteln eine gut brauchbare Abbildungsleistung erschlossen. Dabei führt der hohle Frontmeniskus nicht nur eine wesentliche Verbesserung des Lagenverlaufs der beiden astigmatischen Bildschalen herbei, sondern es wird auch noch eine wesentliche Verbesserung der Verzeichnung erreicht, die bekanntlich bei Linsenanlagen mit Hinterblende meist unerwünscht große und störende Beträge er-Despite the simple structure of the lenses, which also only contains spherical surfaces, with the simplest technical means developed a usable imaging performance. The hollow leads Front meniscus not only significantly improves the position of the two astigmatic ones Image scales, but a significant improvement in the distortion is also achieved, which, as is well known, usually undesirably large and disruptive amounts in lens systems with rear diaphragm.

reicht, selbst wenn diese als 6- oder 71insige Objektivanlagen erstellt werden.is enough, even if these are created as 6- or 71-inch lens systems.

Hierzu 1 Blatt Zeichnungen1 sheet of drawings

Claims

Patent claims:

1.Photographic objective of the two-lens achromatic type with rear aperture, consisting of two meniscus-shaped partial elements, which turn their convex outer surfaces against each other, and of which one partial element is composed of two individual lenses of opposite strengths, the inner neighboring pair of surfaces designed as a cemented surface or separated by a small air space can be, characterized in that the sub-members face both the side of the longer conjugate and the side of the shorter conjugate or the rear panel each have a concave outer surface and the dimensioning in accordance with the following data values for the radii. Vertex spacing and breakage occurs:
/ = 100 mm relative opening 1: 6.8

Radii

Thick and
Air clearances

Refractive indices

>u> u

R ₁ = -41.782
A ₁ '= -42.684
R ₂ = +27.037
R ₂ ¹ = -64.063
R ₃ = -64.063
R ₃ ¹ = +38.803

Cl ₁ = 7.51
O ₁ = 0.25

1.523

59.5

d ₂ = 9.012 1.60738 56.65

a ₂ = 0

d ₃ = 2.629 1.02004 36.37

b = 10.00

2. Photographic objective of the two-part achromatic type with rear aperture, consisting of two meniscus-shaped partial members, which turn their convex outer surfaces against each other, and one of which is composed of two individual lenses of opposite strength signs whose inner pair of neighboring surfaces is designed as a putty surface or through a small air gap can be separated, characterized in that the partial links on both the side of the longer as well as the side of the shorter conjugate or the rear panel each have a concave outer surface and that the dimensioning is carried out in accordance with the following data values for the radii, vertex distances and refractive indices:

/ = 100 mm -38.373 relative Off η ι ing 1: 8 59.48 Radii Thick and Refractive indices -39.249 Air clearances /Irf V/ Irf V R ₁ = + 30.004 49.40 rf, = 12.11 1.52249 R ₁ = -25.430 O ₁ = 0.61 R ₂ = -25.430 36.37 c! ₂ =: 11.34 1.60729 R₂' =R ₂ '= +40.729 a ₂ = 0 R ₃ = rf ₃ = 5.75 1.62004 R ₃ = A - = 9.65

The invention relates to a photographic object Achromat-type with posterior end, consisting of two meniscus-shaped partial limbs, which are convex Outer surfaces turn against each other, and one of which is a partial limb of two individual lenses opposite one another Strength sign is composed, the inner adjacent pair of surfaces formed as a putty surface or can be separated by a small air space.

ίο The subject of the invention is a further development of the twin-lens cemented Aehromat with rear panel, as it has been used as a photographic object.
Compared to those used as telescopic lenses, completely different requirements are placed on these achromatic lenses. Even with these, there is a requirement for correction of the aperture error, the chromatic longitudinal and transverse aberration as well as the fulfillment of the sine condition (coma correction).

The much larger field of view (up to 50) in photographic recordings, however, requires the additional Correction of field curvature, astigmatism and distortion. The usable focal ratio should be in the range 1: 6 to 1: 8. These requirements make the area of validity the third-order aberration is exceeded, and the consideration is also required the higher-order error components are indispensable. However, this exceeds the number of errors to be corrected that of the available, free construction parameters. An exact numerical solution isn't even possible for the third-order aberrations mentioned. According to the invention, the task of further development of the two-lens cemented achromatic lens with rear panel solved by the fact that the partial links both the side of the longer conjugate and the side of the shorter conjugate or the rear panel each one turn concave outer surface and that the formation of the two meniscus-shaped partial members according to one of the data tables listed in the characterizing part of the two patent claims takes place.

It has been found that it is advantageous for the solution of the underlying problem that the Lenses according to the invention meet the following conditions at the same time:

a) The absolute value of the arithmetic sum of the outer radii A ₁ and A ₁ 'bordering on air of the meniscus bordering on the longer conjugate should be less than 1.0 /, but not be less than the lower limit of 0.60 · /.

b) The absolute value of the difference between these two radius lengths should be equal to or greater than zero, however, do not exceed an upper limit of 0.15 · /.

c) The quotient of the front hollow radius R ₁ and the radius R _{% of} the convex front surface of the collecting and the shorter conjugate facing rear rear phalanx should be greater than 1.20 in terms of its absolute value without exceeding an upper limit of 2.10.

d) The axial thickness ^ _{1 of} the front meniscus should be between 0.05 · / and 0.20 · /.

e) The sum of _{the refractive powers ^ 1} '+ φ ₂ = ψ of the rear surface of _{the front meniscus (A 1} ') and the front surface of the following doublet (R ₂ ) should be greater than 2.5 times the refractive power Φ of the entire lens, without the To exceed 4 times.