w WV

7 JJSROR

arVFu?.

2.975,673

March 21, 1961

Ulji:yW. MANDLER ETAL

2,975,673

HIGH APERTURE PHOTOGRAPHIC OBJECTIVE

22 4 3w

I-6X243

Filed Aug. 26, 1959-- - - -x

d-r-----Xd
INVENTORS:

AwaA7AA /7A/VAAAA e-AA/C/ WGAMAA

BY

i4 W. Hall

United States Patent Office Patented Mar.2,975,673
21, 1961
2,975,673
BGBAPERTURE PHOTOGRAPHC OBJECTIVE

2and emerging lens surfaces, respectively, and to the succession of such surfaces in the direction of the incidenceof light into the objective generally.

The invention will be exemplified in connection with
two specific embodiments of high aperture Gauss-type
photographic objectives schematically illustrated in Figs.
1 and 2 of the accompanying drawing.
SE
Midland,
Ontario,
Canada,acompanyofada
The following Tables 1 and 2 correspond to the embodi
ments of Figs. 1 and 2, respectively, r1 to r indicating
Filed Aug. 26, 1959, Ser. No. 836,195
O the radii of curvature of the objective lenses, d to di
Claims priority, application Germany Aug. 30, 1958
the thickness of the lenses, a to a the distance of thelenses from each other while as indicates the distance of
2 Claims. (C. 88-57)
the last lens from the image-receiving photo-sensitive surrefraction for the e-line, a theThe present invention relates to a high aperture photo 15 face x, in the index of andD the objective diaphragm.
graphic objective (high power objective) of the Gauss coefficient of dispersion, Table
1type. Such objectives may comprise, in the direction
Focal length fr=1.0 Angle of image as 64
Relativeof the incidence of light, a positive lens facing the object
aperture i:1.4)
and a cemented negative meniscus on one side of thediaphragm, and a positive lens, another cemented nega 20
fetive meniscus, and another positive lens on the otherside of the diaphragm between the diaphragm and ar1 -- 0.84171
photo-sensitive surface.
du0.1000 1,7234
r a 2,5689
The objective of this invention is a modification of theaa 0.0006
Gauss-type objective above described, with its compound 25
r xt -- 0.3842
da0,1297
1,7899negative meniscus lenses preferably having concave surra-- 0.8639
faces facing the diaphragm.
de O.0374
1.7.0444

Walter Mandler and Erich Wagner, Midland, Ontario,
Canada, assignors to Ernst Leitz Canada Ltd., Optical

In such objectives, it is not easy to make the Zone of
the sagittal curvature of the field of view small. In
presently available Gauss-type objectives of a focal length 30of 50 mm., the size of this zone is between about 0.15mm, and 0.20 mm.
With a view to reducing the zone of the sagittal curva
ture of the field of view Gauss-type objectives of the indicated type have been proposed, wherein a positive lens 35
is inserted between the two negative meniscus lenses.
However, no appreciable reduction of the zone of thesagittal curvature of the field of view was accomplishedwith these objectives because the added positive lensT -- 0.2552

r - 1.6077
r a - 0.8639
r - 0.3448
r - 1,374
rt - 0.4575
films -20.0000
rat - 0.8417

must be considered as separate from the adjacent meniscus 40

since the difference of the adjacent lens surface radii isso small that the occluded air lens has almost the same
effect as a zero lens.

as 0.2309
d0,0554
ass0,0494

7899

duo,0374

1,76167

dar 0.1314

17899

a 0,0171d=0.137
ass0.5469

172056

Table 2
(Focal length far 1.0

Angle of image = 45°
aperture 1:1.4)

Relative

It is the primary object of the present invention to
produce a high aperture objective of the above type, 45

wherein the zone of the sagittal curvature of the field of
du0,0894 1,72056 47,69
view is considerably reduced and wherein the meridional
as0.0078
component of the sagittal coma is almost completelyeliminated.
d=0.348
1,7899 48.0
The above and other objects are accomplished in ac 50
d=0.0388 1,70444 29,84
cordance with this invention by forming the positive lens
ass0,2400
between the two negative meniscus lenses as a concave
T -1.6720
meniscus whose back surface has a radius at least twice
da0.0576 1,7899 48.0
r = -0.8984
as large as the radius of the adjacent front surface of theat 0, 054
r as -0.3562
succeeding cemented negative meniscus, the focal length 55
disr0.0388
1.76167of this positive lens being larger than the total focal lengthr is -1.9892
of the objective.
da:0.1800 17899
rt= -0.4858
Preferably, the back radius of the positive lens is about
as 0.0078
ris co2.4 to 2.6 times as large as the front radius of the sucdistO.0756
1.7899ceeding meniscus. The focal length of the positive lens 60
fire -1.0658
ass0, 616
is preferably about 2 to 2.5 times the focal length of theobjective.
According to one preferred embodiment of the in
In the drawing, r1 and r constitute the front and backvention, the radius of the concave surface of the ceradii
the first positive lens, d being its thickness, amented negative meniscus arranged between the object 65 is theofdistance
between the positive lens and the sucand the diaphragm, which faces the diaphragm, is smaller
ceeding
cementednegative meniscus composed of a lens
than the sum of the thickness of the positive meniscus
ofthethicknessd,with front radius r and back radius rlens and its distance from said concave surface. Preferand a lens of the thickness d with front radius r andably, the radius is between about 85% and 95% of thisback radius rs, the concave surface with the radius r
S.
70 facing the diaphragm D. On the other side of the dai
Throughout the specification and claims, the terms"front," "back" and "succeeding" refer to the incident phragm and at a distance a from the last-named concave

lens surface, there is arranged the concave positive

2,975,678

34.

meniscus lens of thickness d with front and back radii

jective lenses, d to di the thickness of the lenses, a toas the distance of the lenses from each other, as thedistance of the last lens from the image-receiving photosensitive surface x, in the index of refraction, and athe coefficient of dispersion.
2. A high aperture photographic objective having adiaphragm and comprising, in the direction of the incidence of light, a first positive lens; a cemented negars and r, succeeded at a distance as by a cemented negative meniscus composed of a lens of the thickness dis
with front and back radii r and r and a lens of thethickness dis with front and back radii r and rio, theconcave surface of the meniscus with the radius ris facing

the diaphragm D. The final lens between the last-named
meniscus and the image-receiving surface x is spacedfrom the meniscus by distance a has a thickness d, andfront and back radii r1 and ri.

While two specific examples of high aperture photographic objectives have been set forth for purposes ofillustration, it should be clearly understood that many

variations and modifications may occur to the skilled in
the art, particularly after benefiting from the presentteaching, without departing from the spirit and scope of
the invention as defined in the appended claims,

tive meniscus lens between the first positive lens and thethe other side of the diaphragm; a positive concave
meniscus lens between the diaphragm and said othercemented negative meniscus lens, the positive concave

O diaphragm; another cemented negative meniscus lens on

meniscus lens having a back surface with a radius which

5 is at least twice as large as the radius of the front surface of said other cemented negative meniscus lens anda focal length which is larger than the total focal lengthof the objective; and a final positive lens succeeding said
1. A high aperture photographic objective having acemented negative meniscus lens, said objective
diaphragm and comprising, in the direction of the in 20 otherbeing characterized by the following data:
E. light, a first positive lens; a cemented nega
Focal length fs= 1.0 Angle of image: 45°
Relative
aperture 1 : 1.4
tive meniscus lens between the first positive lens and thediaphragm; another cemented negative meniscus lens on
the other side of the diaphragm; a positive concave
smeniscus lens between the diaphragm and said other ce 25
ris --0, 8824
mented negative mcniscus lens, the positive concave
dise 0.0894
72056
meniscus lens having a back surface with a radius whichr = +2.7880
We claim:

is at least twice as large as the radius of the front sur
a focal length which is larger than the total focal length 30

face of said other cemented negative meniscus lens andof the objective; and a final positive lens succeeding saidother cemented negative meniscus lens, said objective
being characterized by the following data:
Focal length f=10

Angle of image=64

aperture 1: 1.4

Relative

r: s --0.3996
rise --0. 8984

ris --0.2654

35

a -1. 6720
ry -0, 8984
T is -0.3562
r is -1.9892

Tus 0.4858

r at -0.871
r -2.5689
r --0, 3842
res --0,8839
r --0.2552
r a -1.6077
r as -0.8639
r = -0.3438
r = -1.3714

ris -0.4575
ris -20.0000
ris -0.8417

duo. 1000
as0.0006
d0.1297
darO.0374

1.72341, 50.10
17899 480
1,70444 29.84

rt doris -1.0658

17899

76167
i.7899am 0.0078
due 0.0756
a 0.616

wherein r to r indicate the radii of curvature of theobjective lenses, d to d the thickness of the lenses, ato a the distance of the lenses from each other, as thedistance of the last lens from the image-receiving photosensitive surface x, in the index of refraction, and ue
the coefficient of dispersion.
50
References Cited in the file of this patent

17899

48.0

1.761817899

48.0

172056

7,6927, 34

as 0.017

da O. 137
as 0.5469

d0.0388
da0.1800

7899

17044445

as O. 2309

de O,0554
are 0.0494
dra O. 0374
dis0.1314

O

as 0.0078
das 0, 348
d=0.0388
as 0.2400
dO,0576
as 0.0514

UNITED STATES PATENTS

wherein r to raindicate the radii of curvature of the ob

2,171,641

Berek ---------------- Sept. 5, 1939

55 2,715,354

Suzuki et al. ---------- Aug. 16, 1955
FOREIGN PATENTS

456,912

Germany -------------- Mar. 5, 1928