Nikon S-kt - Page 24

(4)
Condensers
These condensers
are
not only
capable of concentrating the
light-beam for
better
illumination of the image field,
but also
greatly
influence the
resolution of the
microscope image, image contrast
and depth
of focus. For more critical observation and
photomicrography,
the use of
an achromat
or achromatic-aplanat
condenserprovided
with
an
oblique
illumination device and
a
filter
holder is
specially
recommended.
(5)
lllumination System
As shown
in
Fig.26,
the
light emitted from the lamp
is collected
by the collector
lens and
transmitted as
a
parallel
bundle
to the mirror. A
fine
diffusing
filter,
serving
to
make the
illumination uniform,
provides
the entire
viewfield
with
even
light.
The light bundle,
collected by
the illumination
field
lens onto the
front
focal
plane
of the condenser,
covers
the opening of
the condenser iris diaphragm.
The
illumination
field
diaphragm
is imaged by the
illumination
field
lens and condenser
lens onto the
specimen
plane.
Thus, the
illumination system
of the microscope
model
S-Kt
fulfills
all the
requirements
for
Koehler
type illumination
over a wide
range
so
as to
offer uniform
image
brightness
for
the 4X
objective as
well
as
to cover the aperture
angle
of the highest
power
objective.
Table
8
Type Numericsl Aporturs Remarks
Abbe
1.30
For central illumination
(without
oblique illumination
slider)
1.30
For
central
and
oblique illumination
(with
oblique
illumi nation
slider)
Aplanat 1.40
For
increased i | | umi nation
(f
I uorescence
m icroscopv
)
Achromat 1.25 For critical microscopy
Achromatic-aplanat 1.40
For
best image
quality
Phase Turret 1.30
With turret-mounted annular diaphragms
for
phase.
contrast microscopV
L,W.D.
Turret 0.70
Working
distance
10
-
2Omm.
With turret-mounted
annular diaphragms
for
phase-contrast
and
phase-
interference microscopy.
External
L.W.D, Turret
0.40
Working
distance
30
-
60mm.With
turret-mounted
annular
diaphragms
for
phase{ontrast
microscopy-
Universal
Dark-Field 1.20-1.40
For
dark-field
microscopy.
Supplied in
centerable mount.
With
outer
diameter 36.8mm. To be used with objectives
IOX to 100X. ldeallv
suited
for fluorescence work.
100X
objective used
should
have built-in adjustable
iris diaphragm
orfunnel
stop.
Thickness of slide
glass
used
should
be less
than 1.2mm.
Low-Power o.32
For
low-power
macro-objectives,e.9. 1.2X,2X and 3X
Plan
Achromats.
25