Aperture Diaphragm; Use With Rechargeable Batteries; Use Of The Polarizer (Optional) - Optika B-150D Serie Manuel D'instructions

8.7

Aperture diaphragm

• The Numerical Aperture (N.A.) value of the ap-
erture diaphragm affects the image contrast. In-
creasing or reducing this value one can vary res-
olution, contrast and depth of focus of the image.
Move the diaphragm lever ① (Fig. 13) toward left
or right to decrease or increase the N.A. value.
• With low contrast specimens set the numerical ap-
erture to about 70%-80% of the objective's N.A. If
necessary, remove on eyepiece and, looking into
empty sleeve, adjust the condenser's diaphragm
in order to obtain an image like the one in Fig. 14
8.8

Use with rechargeable batteries

When the microscope is plugged with the power
supply, the LED indicator for the battery recharge ②
is lit. (Fig. 15)
• LED red: battery under charge
• LED green: battery fully charged.
When the microscope is unplugged, the LED is off.
During the normal use with batteries, LED is always
OFF.
8.9

Use of the polarizer (optional)

1. Remove the specimen from the stage.
2. Looking inside the eyepieces, rotate the polarizer
until the darkest position is achieved.
3. Once the dark is achieved ("extinction" or
"Crossed Nicol" position) it is possible to begin
the observation.
APERTURE
DIAPHRAGM
FIELD OF VIEW
②
Page 12
①
F ig. 13 F ig. 13
70-80%
30-20%
F ig. 14 F ig. 14
F ig. 15 F ig. 15