Centering Of Aperture Diaphragm - Nikon Epiphot 300 Manual

5. Centering of Aperture Diaphragm

( 1) Push the mirror block changeover lever to put the brightfield mirror block in the
optical path.
(2) Push both the OB/PHOTO•SIDE and OB/PHOTO changeover levers to provide the
binocular eyepieces with 100% light output.
(3) Tum on the power switch of the power supply unit. Rotate its lamp intensity control
dial to CTRL. Set the lamp intensity control dial of the microscope base at about 6V.
(4) If a Nomarski prism, the polarizer and the analyzer are in the optical path, remove
them from the optical path.
(5) Fully open the aperture and field diaphragms.
(6) Rotate the revolving nosepiece to switch to the IOx objective.
Rotate the stage movement knobs to locate the center of the opening in the stage ring
almost right above the top of that objective.
(7) Place a flat, high reflectance sample on the stage. Face its surface to be observed
downward.
(8) Rotate the coarse focus and fine focus knobs to focus on the sample.
Stop down the field diaphragm to make the field diaphragm image clearly visible.
This makes focusing easier.
(9) Switch from the IOx objective to the 50x objective and focus on the sample again.
( 10) Insert each of the two centering tools into the screw holes for aperture diaphragm
centering.
( 11) Remove one of the binocular eyepieces to view
the viewfield through the eyepiece sleeve. The
objective's exit pupil is visible there as a bright
circle. Also visible there is the diffuser plate built
in the illuminator.
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