DN117D-LED
I-SCOPE OPTICS JAPAN
12
3.3.4 Condenser Adjustment
（
Fig.20
）
Turn the condenser focus knob to move
the condenser up and down. Raise the
condenser
when
using
the
high
magnification objective, and descend it
when using the low magnification one.
The condenser and the objective are
coaxial. It has been adjusted well before
leaving factory, so the user needn’t to
adjust them by self (the distance between
the top of the condenser and the stage
should
be
in
the
range
of
0.03mm~0.4mm.)
The highest position of the condenser has
been adjusted too. It also needn’t any
user’s operation
.
3.3.5
Aperture
Iris
Diaphragm
Adjustment
（
Fig.20,21
）
Turn the aperture iris diaphragm lever
①
to adjust the aperture iris diaphragm.
●
Generally, setting the aperture iris
diaphragm to 70- 80% of the N.A. of the
objective in use will provide an image
with good contrast.
●
If the size of the aperture diaphragm
minified,
the
brightness
and
the
resolution declined, while the contrast
and the depth of field increased; In
other words, if the size largen, the
brightness and the resolution improved,
but the contrast and the depth of field
declined.
●
Generally, setting the size of the
condenser
aperture
diaphragm
at
70%
～
80% of the numerical aperture,
you can obtain a clear image with
enough contrast. If the open of the
aperture diaphragm is too small, the
resolution were very low, so please don’t
minify the aperture below 60% of the
objective’s numerical aperture unless in
a special case, for instance, observating
an almost transparent specimen.
①
Fig.20
Magnification
：
10
×
N.A.
：
0.25
Fig.21
Specimen
Image of Aperture Iris Diaphragm
