Zeiss Axiovert 200 - Objectives

INSTRUMENT DESCRIPTION
Carl Zeiss Objectives Axiovert 200
1-10 B 40-080 e 03/01
1.4 Objectives
The objectives are the optical centerpiece of the microscope. The following is an example of how
objectives can be labelled:
A-Plan 10×/0.20 HD ∞/-
Key:
10× objective magnification, with a color ring on the objective being allocated to each magnification
step (Zeiss color code)
0.20 numerical aperture
HD reflected-light brightfield and darkfield objective
∞ infinite tube length
- can be used without cover slip (D = 0 mm) or with cover slip thickness D = 0.17 mm
or
0 can only be used without cover slip (D = 0 mm)
0.17 can only be used with cover slip thickness D = 0.17 mm
and
Oil oil immersion objective
Ph 2 phase contrast objective with a green color ring and phase stop Ph 2
Color ring code for objective magnification:
Color ring on
objective
black brown red orange yellow green light
blue
dark
blue
white
Magnification
factor
1.25× 2.5× 4×; 5× 6.3× 10× 16×;20×;
25×; 32×
40×; 50× 63× 100×;
150×
The objective magnification (e.g. 10x) multiplied with the eyepiece magnification (e.g. 10x) and the
Optovar magnification (e.g. 1.6x) results in the visual overall magnification;
example: 10 x 10 x 1.6 = 160x.
The numerical aperture x 1000, e.g 0.20 x 1000 = 200x, is the highest useful magnification, i.e. no
further details are resolved above that limit.
In transmitted-light applications, the exact observance of the cover slip thickness of 0.17 mm is all the
more necessary the higher the numeric aperture of the objective. Therefore, so-called "corr" objectives
can be set for different cover slip thicknesses via a correction ring. For this, a specimen area is searched,
and the position of the correction ring where optimum focus and image contrast are obtained is
determined (refocusing is always required).
Immersion objectives are always insensitive to differences in cover slip thickness.
When immersion objectives are used, the air between the cover slip and the objective is replaced with a
liquid, which is immersion oil in most cases.