Nikon DS-L4 Instructions Manual page 182

Symptom
The contrast is low.
The image quality is poor.
Chapter 16
Possible Cause
The illumination is too bright or too dark.
Light around the subject affects contrast.
In the optical device (microscope) side,
the setting of field diaphragm and
aperture diaphragm is incorrect.
In the optical device (microscope) side,
filter selection is incorrect.
The contrast of the subject itself is low.
The image adjustment is incorrect.
The camera gain is set too high.
174
Troubleshooting
Adjust the brightness of the illumination properly.
Adjust the exposure.
Darken the interior, or place caps on the binocular
eyepieces of the microscope.
Adjust the field diaphragm to a size that circumscribes
the field of view. Adjust the aperture diaphragm to 70 to
80 percent of the numerical aperture of the objective.
For a phase contrast microscope or interference
microscope (dual beam or multiple), insert the specified
filter. For negative-positive images, generally, inserting
a green interference filter (GIF) improves contrast.
Inserting a complementary color filter of the color of the
specimen increases contrast.
Consider the illumination or microscopy method.
Set the CHRM, HUE, contrast, or SFT properly in the
[CAMERA MENU: IMAGE] window.
Noise due to high camera gain results in a coarse
image. Adjust the brightness adequately, and then
adjust the camera gain and the exposure time.
Action