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

9.7

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 fo-
cus of the image. Move the diaphragm lever ① (Fig. 13) to-
ward 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. 14.
9.8

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)
• Power supply connected, low battery: led turns RED. When
charging is finished, 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
empty: LED is RED.
9.9

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
②
Page 12
①
70-80%
FIELD OF VIEW
F ig. 13 F ig. 13
30-20%
F ig. 14 F ig. 14
F ig. 15 F ig. 15