Leica DM2700 M Bedienungsanleitung Seite 67

Problem
Undesirable stray light.
Phase Contrast
No phase contrast is possible.
Polarization
No polarization contrast is possible.
Transmitted Light Interference Contrast
No transmitted light interference contrast is pos-
sible.
Cause/Remedy
Incident light: Open and center the aperture
diaphragm.
If present, center the lamp housing
(LH106z → 41ff).
Clean the specimen and neighboring lenses
(→ p. 69).
The specimen is too thick, too thin or too
brightly stained.
Refractive indeces of the mounting medium
and specimen are identical, so that there is no
phase jump.
The cover glass is not placed planar.
Check the right light ring (→ p. 59).
Check the centering of the light rings
(→ p. 38f).
Check the condenser centering.
Open the aperture diaphragm completely.
Bring the polarizer and analyzer into cross
position until they reach maximum darkness
(without specimen) (→ p. 55f, 60f).
Remove the ICR/ICT prism.
The specimen is too thick or too thin.
The embedding medium or specimen are of bi-
refringent material. Rotate the specimen.
The difference in the refractive indices of the
specimen and the embedding medium is too
small.
11. Trouble Shooting
67