Aperture Diaphragm; Use With Rechargeable Batteries; Use Of The Polarizer (Optional) - Optika B-150 Serie Manual De Instrucciones

9.8

Aperture diaphragm

• The Numerical Aperture (N.A.) value of the aperture dia-
phragm affects the image contrast. Increasing or reducing
this value one can vary resolution, contrast and depth of
focus of the image. Move the diaphragm lever
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, looking into empty sleeve, adjust the con-
denser's diaphragm in order to obtain an image like the one
in Fig. 16.
9.9

Use with rechargeable batteries

This operation can be done only with "R" models.
When the microscope is plugged with the power supply, the LED
indicator for the battery recharge
• 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.

9.10 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 "Crossed Nicol"
position) it is possible to begin the observation.
(Fig. 15)
①
is lit. (Fig. 17)
②
APERTURE
DIAPHRAGM
FIELD OF VIEW
②
Page 15
①
F ig. 15 F ig. 15
70-80%
30-20%
F ig. 16 F ig. 16
F ig. 17 F ig. 17