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Using the aperture diaphragm (AS) for transmitted light observation
Rotate the aperture diaphragm ring a to set the index to 70% of the
numerical aperture of the objective.
While looking at the observed image, rotate the aperture diaphragm
ring a to fine-adjust it to obtain the desired image.
To check the outer diameter of the aperture diaphragm,
remove the eyepieces and look into the eyepiece sleeves to
view the aperture diaphragm image with respect to that of the
objective pupil. In general, it is appropriate to set the sample
used with the microscope between 70% and 80% of the
numerical aperture of the objective, but you can narrow down
the numerical aperture furthermore as needed.
Using the field diaphragm (FS) for transmitted light observation
Rotate the field diaphragm lever b to adjust the field diaphragm.
Field diaphragm ring index position
Field
diaphragm
Open to
maximum
Close to
minimum
Narrowing down the field diaphragm so that the field
diaphragm image is circumscribed to the field of view
depending on each objective you use will cut off the internal
reflection and back light from the sample to improve the
image contrast.
1
2
TIP
1
TIP
70 to 80%
30 to 20%
Pupil diameter of
objective
a
b
