Optical system

1. An optical system for arranging between a light source and a field diaphragm in an illumination beam path of a microscope, comprising:

n imaging optical elements with focal lengths f i and Abbe numbers ν i (i=1, . . . , n) and for which the following relationship is met:

∑

i

=

1

n

⁢

h

i

f

i

·

v

i

≤

0.07

,

where h i is one half of the bundle diameter of a bundle of light rays proceeding from a point of the light source at the entrance to the imaging optical element I;

wherein the n optical elements comprise a partial system which serves to image the light source from infinity to an intermediate image in the optical system, has a focal length f and comprises in direction of the beam path proceeding from the light source: a first converging lens with a focal length f i where 0.3·f<f i <0.7·f, a diverging lens with a focal length f 2 where −0.2·f<f 2 <−0.4·f, a second converging lens with a focal length f 3 where 0.3·f<f 3 <0.7·f, and a third converging lens with a focal length f 4 where 0.8·f<f 4 <2·f, wherein the distance of the third converging lens from the second converging lens ( 20 ) is between 0.6·f and 1.2·f.

2. The optical system according to claim 1 ;

wherein the Abbe number of the material of the first and/or second converging lens of the optical partial system is greater than 60.

3. The optical system according claim 1 ;

wherein the Abbe number of the material of the diverging lens of the optical partial system is less than 50.

4. The optical system according to claim 1 ;

wherein the Abbe number of the third converging lens of the optical partial system is greater than 50.

5. Optical system according to claim 1 ;

wherein the distance between the first converging lens and the diverging lens of the optical partial system and the distance between the diverging lens and the second converging lens of the optical partial system are less than 0.05·f.

6. The optical system according to claim 1 ;

wherein the optical partial system has a focal length f=50.76 mm and the parameters radius r 1 of the entrance surface, thickness d of the lens, radius r 2 of the exit surface, distance a to the following lens, refractive index n at a wavelength of 546.1 nm, and Abbe number ν have the following values:

r 1

d

r 2

a

Lens

in mm

in mm

in mm

in mm

n

ν

first

32.08

8.00

−23.21

1

1.49

70.18

converging

lens

diverging

−21.91

3.00

16.55

1.11

1.65

33.6

lens

second

18.97

11.00

−23.21

46.81

1.49

70.18

converging

lens

third

15.18

3.00

30.07

50.48

1.52

63.96.

converging

lens

7. The optical system according to claim 1 , which has seven lenses and in which the parameters radius r 1 of the entrance surface, thickness d of the lens, radius r 2 of the exit surface, distance a to the following lens, refractive index n at a wavelength of 546.1 nm, and Abbe number ν have the following values:

r 1

d

r 2

a

Lens

in mm

in mm

in mm

in mm

n

ν

first

−141.25

7.2

−12.23

0.3

1.46

67.77

collector lens

second

54.25

5.8

−25.12

40.09

1.52

59.22

collector lens

first

32.08

8

−23.21

1.00

1.49

70.18

converging

lens of the

first partial

system

diverging

−21.91

3

16.55

1.11

1.65

33.6

lens of the

first partial

system

second

18.97

11.00

−23.21

46.81

1.49

70.18

converging

lens of the

first partial

system

third

15.18

3

30.07

50.48

1.52

63.96

converging

lens of the

first partial

system

lens of the

−392.44

6.5

−24.58

1.52

63.96.

second

partial

system

8. A microscope, comprising:

an optical system arranged between a light source and a field diaphragm in an illumination beam path of the microscope;

wherein the optical system comprises:

n imaging optical elements with focal lengths f i and Abbe numbers ν i (i=1, . . . , n) and for which the following relationship is met:

∑

i

=

1

n

⁢

h

i

f

i

·

v

i

≤

0.07

,

where h i is one half of the bundle diameter of a bundle of light rays proceeding from a point of the light source at the entrance to the imaging optical element i.