Restricting The Illumination To The Area Of The Sample Being Viewed (Centering And Adjusting The Field Diaphragm) - Nikon Eclipse Ni-E Instruction Manual

Aperture diaphragm
The aperture diaphragm is used to adjust the numerical aperture
of the illumination system. Under epi-fluorescence microscopy, it
is also used to adjust the brightness of the image, as well as the
size of stray light.
Turning the aperture diaphragm lever of the epi-fluorescence
attachment changes the size of the aperture diaphragm.
Pushing in the lever opens the aperture diaphragm while pulling
it out closes it. Stopping down the aperture diaphragm reduces
stray light, but will also make the image darker. Conversely, a
larger aperture diaphragm size increases the brightness, but
may also increase the amount of stray light. For standard
epi-fluorescence microscopy, keep the diaphragm open, and
stop down as necessary to adjust the image brightness.
Be sure to center the aperture diaphragm of the
epi-fluorescence attachment as follows before use.
■ Centering the aperture diaphragm
(1) Close the shutter of the epi-fluorescence cube turret.
(2) Replace one objective on the nosepiece with the
centering tool.
(3) Under epi-fluorescence microscopy, focus on the
sample.
(4) Bring the centering tool into the optical path.
(5) Pull out the aperture diaphragm lever to stop down the
diaphragm.
(6) While watching the screen on the centering tool, turn the
aperture diaphragm centering screw with the provided
hex wrench (opposite side distance: 2) to move the
aperture diaphragm image to the center of the screen.
Be sure to look straight at the screen.
Restricting the Illumination to the Area of the Sample Being Viewed (Centering and
17.5
Adjusting the Field Diaphragm)
The field diaphragm is used to restrict illumination to the area of
the sample being viewed.
Turning the field diaphragm lever of the epi-fluorescence
attachment changes the size of the field diaphragm. Pushing in
the lever opens the field diaphragm while pulling it out closes it.
For normal observations, stop down the diaphragm so that the
aperture boundaries circumscribe or inscribe the field of view.
Opening the field diaphragm too much and illuminating a broader
area than necessary will result in stray light entering the field of
view, generating flare and reducing the image contrast. In
addition, the sample will become decolorized over a wider area.
Be sure to center the field diaphragm of the epi-fluorescence
attachment as follows before use.
■ Center the field diaphragm
(1) Pull out the field diaphragm lever on the
epi-fluorescence attachment to stop down the field
diaphragm.
(2) Turn the field diaphragm centering screw with the
provided hex wrench for M4 setscrew to move the field
diaphragm image to the center of the field of view.
(3) Push in the field diaphragm lever and open the field
diaphragm to match the size of the field of view.
(4) Turn the field diaphragm centering screw once again to
align the center of the field diaphragm image with the
center of the field of view.
Field diaphragm adjustment timing
Be sure to adjust the size of field diaphragm each time you change the objective. While it is not absolutely essential to
center the field diaphragm each time you change the objective, you should still perform a quick check and make
adjustments as necessary.
Chapter 3
Individual Operations
76
P
F. S T O
Aperture diaphragm
centering screws
Aperture
diaphragm
ring
Centering tool
Adjusting and centering the aperture diaphragm
Diaphragm
P
F. S T O
opens
Field diaphragm
Field diaphragm
centering screws
Field diaphragm
image
Eyepiece field ring
Adjusting the field diaphragm
Diaphragm
A . S T O P
opens
Diaphragm
closes
Aperture diaphragm
lever
FN- S2N JAPA
N
40x
10x
P
A . S T O
Diaphragm
closes
lever
Field diaphragm
image
Eyepiece field ring