Optika Italy B-383 Series, Instruction Manual

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Page 16
12.5 Use of aperture diaphragm (AS)
The numerical aperture value (N.A.) of the aperture diaphragm
affects image contrast. Increasing or decreasing this value ac -
cording to the numerical aperture of the lens changes the resolu -
tion, contrast and depth of field of the image.
1. Move the aperture ring
④
(Fig. 24) to open or close the dia -
phragm to the desired position.
• For low-contrast specimens, set the numerical aperture
value to approximately 70%-80% of the objective’s N.A. If
necessary, remove an eyepiece and, looking into the empty
eyepiece holder, adjust the condenser ring until an image like
that in Fig. 19 is obtained.
12.6 Use of color filters
1. Insert the filter
①
in one of the two slots
②
placed in the
upper part of the reflected light illuminator. (Fig. 25).
Filter Application
Blue Converts the source color temperature to
daylight
Green
Increases the contrast in black and white
photography
Yellow Contrast filter for the observation of wafers
and semiconductors
Frosted white Reduces lighting irregularities by creating a
homogeneous field of view
F Fig. 24 ig. 24
④
F Fig. 26 ig. 26
F Fig. 27 ig. 27
F Fig. 25 ig. 25
①
②
12.7 Use of polarized light
1. Insert the polarizer all the way into the optical path. (Fig. 26)
2. Insert the analyzer all the way into the optical path. (Fig. 27)