Aperture Diaphragm; Use With Rechargeable Batteries; Use Of The Polarizer (Optional) - Optika Italy B-150 Series Instruction Manual

8.8

Aperture diaphragm

• The Numerical Aperture (N.A.) value of the aper-
ture diaphragm affects the image contrast. Incre-
asing or reducing this value one can vary reso-
lution, contrast and depth of focus of the image.
Move the diaphragm lever ① (Fig. 15) toward left
or right to decrease or increase the N.A. value.
• With low contrast specimens set the numerical
aperture to about 70%-80% of the objective's
N.A. If necessary, remove on eyepiece and, lo-
oking into empty sleeve, adjust the condenser's
diaphragm in order to obtain an image like the
one in Fig. 16.
8.9

Use with rechargeable batteries

This operation can be done only with "R" models.
When the microscope is plugged with the power sup-
ply, the LED indicator for the battery recharge ② is
lit. (Fig. 17)
• 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.
8.10

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 "Cros-
sed Nicol" position) it is possible to begin the
observation.
APERTURE
DIAPHRAGM
FIELD OF VIEW
②
Page 14
①
Fig. 15
70-80%
30-20%
Fig. 16
Fig. 17