Objectives - Zeiss Axiotech Operating Manual

Axiotech and Axiotech
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Objectives

The objectives are the optical centerpiece of the microscope. The following is an example of how
objectives can be labeled:
Epiplan 10×/0.20 HD ∞/-
where
10× is the objective magnification, with a defined color ring on the objective being allocated to each
magnification step (color coding system from Carl Zeiss)
0.20 is the numerical aperture
HD stands for reflected light, brightfield and darkfield objective
∞
means infinite tube length
- means that use without cover slip (D = 0 mm) or with cover slip thickness D = 0.17 mm is
possible
or
0 means that use is only possible without cover slip (D = 0 mm)
0.17 means that only the cover slip thickness D = 0.17 mm is possible
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 magnifications:
Color ring on black
the objective
Magnification
1.25×
factor
The objective magnification multiplied with the eyepiece magnification (usually 10×) results in the visual
overall magnification; example: 10 × 10 = 100×.
The numerical aperture × 1000, e.g. 0.20 × 1000 = 200×, 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 numerical aperture of the objective. Therefore, so-called "Korr" 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. The plastic oiler containing 20 ml of 581 N immersion oil is
particularly suitable for this purpose.
B 40-020 e 06/99
vario
brown red
2.5× 4×; 5×
orange yellow green
6.3× 10× 16×;20×;2
5×; 32×
Carl Zeiss
light blue dark blue white
40×; 50× 63× 100×;
150×
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