Fein Optic RB50 User Manual - page 17
Fluorescence Assembly:
info@feinoptic.com
Page 16
Centering the Field Diaphragm:
By adjusting the field diaphragm, the beam of light is
adjusted according to the objective and will create
sharper image contrast.
To prevent a fluorescence decrease, narrow the field
diaphragm and reduce the illuminated part of the
sample.
Adjust the field diaphragm to match that of the
objective being used.
Rotate the turntable so fluorescence filter B or G is in
the light path. (If unavailable use another filter).
Rotate the objective to place 10x in the light path.
Push the shutter (1) to “O” open position.
Focus the slide on the stage.
Pull the field diaphragm lever (3) all the way out to
close the field diaphragm to the smallest position.
Push it in all the way to open it to the largest
position.
Look through the eyepiece to view the image of the
field diaphragm.
Adjust the field diaphragm centering screws (2) on
the side of the illuminator with an inner hex wrench
to move the image to the center of the field of view.
Open the field diaphragm gradually. If the image is
centered in the field of view, the diaphragm has
been centered properly.
When using the microscope, open the field
diaphragm a little past the image border in order to
obtain a quality lit image.
Centering the Aperture Diaphragm:
The aperture diaphragm dictates the numerical
aperture (NA) of the illumination system. If the NA of
the illumination system matches the NA of the
objective, the result is better resolution, contrast and
an increase in the depth of field.