OPERATION
ZEISS
Illumination and contrast methods in transmitted light …
Axioscope 5/7/Vario
88
430035-7344-001
03/2018
•
Center the field diaphragm image with both
centering screws (
4
) on the condenser
carrier (
C
).
•
Open the field diaphragm enough to make the
edge of the diaphragm disappear from the field
of view (
D
).
•
To adjust the aperture (contrast), take an
eyepiece from the tube barrel. Looking through
the barrel adjust the aperture with the adjusting
lever (
4
) of the aperture diaphragm to
the size of approx. 2/3 - 4/5 of the diameter of
the objective exit pupil (
E
). In most
cases this aperture gives the best contrast at
almost full resolution and is thus the best
compromise for the human eye.
•
Replace the eyepiece in the tube barrel.
NOTE
Each objective changes the size of the object field and the objective aperture. The centering
might also vary slightly from objective to objective, so that an adjustment of field diaphragm
and aperture might become necessary for optimal results.
With objectives < 10x, the front lens of the condenser (if swivelable) must be swiveled out of
the beam path and the aperture opened fully. In order to achieve a better contrast, the field
diaphragm can be pulled closer when working with large object fields. To do this you must
reduce the opening by a certain range. Avoid closing it too much to guarantee a consistent
illumination of the field of view.
Fig. 4-3
Microscope adjustment in
transmitted light brightfield
microscopy