A
B
Abbe condenser
Beneath the object stage an Abbe condenser N.A. 1.25 is mounted. The condenser can be adjusted in height by
moving the rack and pinion knob beneath the mechanical stage. By adjusting the condenser you can focus the light on
the specimen for a optimized contrast. The condenser is factory pre-centered. If needed, the following procedure can
be followed to center the condenser
1.
Move the condenser to its highest position
2.
Select the 10x objective and place it into the light path and focus the specimen
3.
Rotate the field diaphragm adjustment ring to put the field diaphragm to the smallest position
4.
Adjust the condenser to the point where the image is the sharpest
5.
Adjusting the center adjustment screw and put the image to the center of the field of view
6.
Open the field diaphragm gradually
7.
The condenser is centered correctly if the image remains in the center when you open the field diaphragm and
inscribed to the field of view
The field (Köhler) diaphragm (see A in picture below)
By limiting the diameter of the beam entering the condenser, the field diaphragm can prevent other light from
entering and increase the image contrast. When the image is just on the edge of the field of view, the objective will
show the best performance and obtain the clearest image. The diaphragm is factory pre-centered.
Adjusting the aperture diaphragm (see B in picture below)
•
The aperture diaphragm is used to select the numerical aperture (N.A.) of the illumination. When the N.A. of
illumination matches with the N.A. of the objective, you get the highest possible resolution, depth of field and
contrastare obtained
•
When contrast is low, rotate the diaphragm adjustment ring to 70%-80% of the N.A. of objective this will
improve the contrast of the image. The diaphragm is factory pre-centered
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