Optika Italy B-150R-PL Serie Manuel D'instructions page 15

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 the empty sleeve, adjust the
condenser'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
• Power supply connected, battery low: LED lights RED. When
charging is completed, it turns GREEN.
• Power supply not connected, microscope off: LED is always
OFF.
• Power supply not connected, microscope on, battery
charged: LED is GREEN.
• Power supply not connected, microscope on, battery almost
low: LED is RED.
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.
①
(Fig. 15)
②
is lit. (Fig. 17)
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