Nikon DIAPHOT 300 - Page 56

Symptoms
Causes Countermeasures
Poor image quality
(No effect of phase
contrast; or poor
contrast or
resolution)
Bright field objective is used Use phase contrast objective.
Condenser annular diaphragm
not put in optical path
Select annular diaphragm
(module) that matches Ph code
of the objective. Put it into
optical path.
Phase rings different between
condenser annular diaphragm
and objective
Select annular diaphragm
(module) that matches Ph code
of the objective. Put it into
optical path.
Condenser annular diaphragm
poorly centered
Center annular diaphragm.
Dirt or dust on lens (field lens,
condenser, eyepiece) or culture
container
Clean lens or culture container.
Objective's correction ring not
set to glass (or plastic) thickness
of culture container
Make correction.
Culture container glass (or
plastic) is thicker than 2mm
Use glass (or plastic) not thicker
than 2mm.
Field aperture diaphragm image
not in focus on specimen
surface
Rotate condenser focus knob to
bring field aperture diaphragm
image into focus on specimen
surface.
Uneven focus
Nosepiece not in clickstop
position
Rotate to clickstop position.
Nosepiece incorrectly mounted
Mount properly.
Image shift while
focusing
Specimen tilted on stage
surface
Correctly reposition specimen
on stage.
Nosepiece not in clickstop
position
Rotate to clickstop position.
Nosepiece incorrectly mounted
Mount properly.
Condenser annular diaphragm
off-centered
Recenter condenser annular
diaphragm.
Condenser incorrectly mounted
Mount properly.
Illumination pillar stopped
halfway
Gently bring pillar into contact
with stopper.
Yellowish image
No NCB1 1 filter in optical path
Insert NCB11 filter into optical
path.
Lamp voltage too low
Adjust light intensity control dial
to 9 or PHOTO (for dial on
microscope body) or higher.