Nikon DS-L4 Instructions Manual page 46

16
Adjust the DIA aperture diaphragm.
Press the [A. STOP] button on the DS-L4 screen to adjust the
diameter of the aperture diaphragm.
The aperture should be adjusted to about 70 to 80% of the
numerical aperture of the objective.
Proper size of the aperture diaphragm
Normally, the appropriate size of the aperture diaphragm
is 70 to 80% of the numerical aperture of the objective.
Since an excessively small aperture diaphragm opening
will degrade the image resolution, it is not recommend to
set the aperture diaphragm to less than 60% of the
numerical aperture of the objective.
Adjustment timing for the aperture diaphragm
Be sure to adjust the aperture diaphragm each time you
change the objective.
Calculating the aperture diaphragm diameter
Use the following formula to determine the suitable size of
the aperture diaphragm.
34 x NA x ratio
NA: Numerical aperture of the objective
(Indicated on the side of the objective.)
Ratio: 0.70 for 70％, 0.80 for 80%
<Example>
• Using Plan 40x objective ······ Numerical aperture: 0.75
In this case, the diaphragm diameter to set the aperture
diaphragm of the condenser to 70% can be determined
as follows:
34×0.75×0.70=17.85
Rounded to one decimal place, 17.9 (mm) is calculated.
17
Focus on the sample.
Rotate the focus knob on the microscope main body, ergo
controller, or joystick to operate the elevating section of the
microscope main body.
Chapter 4
Microscopy with DS-L4
1-34
Aperture diaphragm viewed with a
centering telescope
Pupil of
objective
Plan 40X
40x / 0.75
/ -WD
Indication for 40x magnification/
numerical aperture 0.75
Z-axis coordinate
Aperture
diaphragm image
70 to 80
100
Nikon JAPAN
Plan 40x
40x / 0.75
/ -WD