Nikon DS-U2 Instructions Manual page 21

(2) Adjusting the field diaphragm
Adjust the field diaphragm so that it circumscribes the viewfield. Especially for the fluorescent
photo with dark background, be sure to adjust the field diaphragm due to its significant relationship
with contrast. Refer to the instruction manual of the microscope for details on adjustment.
(3) Adjusting the aperture diaphragm
For diascopic illumination:
Generally, the numeric value of the condenser aperture diaphragm is adjusted to
approximately 70% to 80% of the numerical aperture (N.A.) of the objective.
For episcopic illumination:
Generally, the aperture diaphragm is adjusted to approximately 70% to 80% of the size of the
pupil of the objective that can be seen by removing the eyepiece and looking into the
eyepiece tube.
Supplement
* Refer to the instruction manual of the microscope for details on the aperture
diaphragm adjustment.
* To capture the images that have greater depth of focus, decrease the opening size
of the aperture diaphragm. Note that excessively decreasing the aperture may limit
the performance of the objective.
Terms
What is depth of focus?
"Depth of focus" refers to the range along the axis of the field of view over which the image is
in apparent focus. Although decreasing the opening size of the aperture diaphragm extends
the depth of focus, the resolution will be reduced. Adjust the aperture diaphragm considering
your purposes.
(4) Adjusting the focus
Adjust the focus of the microscope so that the image can be clearly seen on the display.
(5) Adjusting the lamp voltage
When photographing a color image, the color reproducibility of the image depends on the lamp
voltage. When a halogen lamp is used as a light source, increasing the lamp voltage produces a
bluish light, while decreasing the lamp voltage produces a reddish light. Except in cases where it is
specifically necessary to adjust the color, the voltage must be set to the proper level for
microphotography, which depends on the microscope in used. (Since this level varies for each type
of microscope, refer to the instruction manual of the microscope.)
When the lamp voltage is changed, readjust the white balance.
Chapter 5 Microscope Setting
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