²
@
Fig. 1
5
Centering the Field Iris Diaphragm
1. Engage the shutter in the light path by pressing the RSHT button on the
hand switch.
2. Engage the B or IB mirror unit in the light path by pressing the MU+ or
MU– button on the hand switch.
(If these mirror units are not available, engage another fluorescence mir-
ror unit in the light path.)
3. Press the RSHT button to open the shutter.
4. Engage the 10X objective by pressing the objective button, place the
specimen on the stage and bring the image into approximate focus.
5. Pull out the field iris diaphragm knob @ to minimize the field iris dia-
phragm.
6. Fit the Allen wrench provided with the microscope frame in the two field
iris diaphragm centering screws ² and adjust them so that the field iris
image comes at the center of the field of view.
7. While pushing in the field iris diaphragm knob @, enlarge the field iris
diaphragm until the field iris image inscribes the field of view. If eccentric-
ity is found after this, try centering again.
8. Enlarge the field iris diaphragm until the iris image becomes almost the
same size as (i.e. circumscribes) the field of view.
Effects of Field Iris Diaphragm
The field iris diaphragm restricts the diameter of light entering the objec-
tive and thus excludes extraneous light, improving image contrast.
To exclude extra light, set the field iris diaphragm knob @ on the reflected
fluorescence illuminator according to the objective power, so that the
image of the field iris diaphragm just circumscribes the field of view.
(Fig. 1)
11