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4.0 ADJUSTING THE MICROSCOPE
4-4 ILLUMINATION UNIT
4-4-1 Using color filters (fig. 20)
Selecting the appropriate color filters according your need.
You can stack a group of color filters in the filter holder, if you
ensure that they are level and that the whole thickness is less
than 11mm.
4-4-2 Using the aperture diaphragm (fig. 21)
When in bright field observation, the aperture diaphragm con
-
trols the numerical aperture of the illumination system. When
the numerical aperture of the objective and the aperture of the
illumination system match, the highest resolution is achieved.
● To identify the aperture diaphragm, the eyepiece can be re
-
moved or the centering telescope can be used. The aperture
diaphragm looks as in fig. 21.
The aperture can be changed by moving the aperture
adjustment lever. ((1)is the image of the aperture diaphragm,
(2) is the edge of the objective).
● Generally, when observing a fully chromatic specimen,
you need to set the size of the condenser to 70-80% of the
aperture of the objective. When observing unstained samples
(e.g. bacteria), start from 70% and slowly turn the aperture
diaphragm lever clockwise.
Figure 20
Figure 21
70-
80%
30-
20%
1
2
70-80%
30-20%
Color filter
Use
IF550
Single contrast color filter (green)
used for phase contrast microscopy
LBD
Color temperature compensation color
filter blue
used for bright field observation and
microphotography
