12
7. The iris (fig. 2, no. 6) can be used to increase the depth of
field. However, a very wide closed aperture reduces the
illuminated field of view. With the adjusting screws (fig. 2,
nos. 11+12) the aperture can be adjusted so that the bright
area is in the center of the image field.
V. INDIVIDUAL OPERATIONS
1. Adjusting the eye relief (see Fig. 5)
Put a specimen on the stage and focus to obtain a clear image
of it. Adjust the interpupillary distance of the binocular tube by
“folding” (1) until the right and left field of view can be com-
posed to one.
2. Diopter adjustment (see Fig. 6)
Put a specimen on the stage. Turn the 40x objective to the
working position. Firstly, observe through the right eyepiece
with the right eye; adjust the coarse and fine focusing knobs
to see clearly. Secondly, observe through the left eyepiece
with the left eye; adjust the diopter adjustment ring (1) to see
clearly.
3. Coarse/fine focusing (Fig. 7)
The instrument uses a coaxial coarse/fine focusing mechanism
to raise or lower the stage. (2) is the coarse focusing knob for
coarse adjustment, (1) is the fine focusing knob for fine adjust-
ment. The smallest graduation on the scale of the fine focusing
knob is 2 μm of vertical.
The tension of the coarse focusing knob is adjustable and pre-
set at the factory for ease of use and to prevent the stage from
unintentionally sliding down. If you wish to adjust the tension,
use the knob for tensional adjustment of focusing (3). Tur-
ning the ring toward the front of the microscope increases
the tension, and toward the rear of the microscope loosens
it. Tension is too high if you experience physical discomfort.
The limit knob (4) prevents accidental contact between longer
objectives and the specimen or the stage. After locking the
limit knob (by turning up and fastening) at a chosen height of
the stage, you cannot focus the object closer to the objective
using the coarse focusing knob. So, the object is protected
against damage. Its use also simplifies focusing (so-called
prefocusing). After changing specimens or objectives, focusing
is easily accomplished by rotating the coarse focusing knob to
reach the pre-focused position. Then make fine adjustments
with the fine focusing knob. Focusing movement with the fine
focusing knob isn’t affected by using the limit knob.
4. Stage (Fig. 8)
The convenient slide holder (1) on the stage is used for holding
the slide glass (2). The longitudinal (lengthwise) adjustment
knob (3) and the transversal (cross) adjustment knob (4) are
coaxial. The stage moves accordingly.