Incident Light Interference Contrast - Leica DM R Serie Mode D'emploi

Incident light interference contrast ICR
Cross p olarizers.
Exactly crossed p olarizers are an essential
requirement for p erfect ICR quality!
Insert the ICR polarizer (29.5) (65.4). Never use a
different incident light polarizer. Switch on
brightfield reflector BF or Smith reflector (Fig.
18); push in diaphragm module (65.9, channel I).
Turn the turret* (65.3) to pos. H (= brightfield).
Align and focus a homogeneous and well-
reflecting specimen.
Insert the IC/P analyser so that the lambda (λ)
engraving is showing (65.1 and 30.5). If using the
360° rotatable analyser (30.1) set the 0 position.
Swivel the analyser round the 0 position until
you obtain the darkest possible setting.
Instead of the polarizer and analyser, the ICR
module (= crossed polarizers) can be used
Choice of IC p rism
Choose the prism in the turret (65.5) that
corresponds to the objective you are using, see
objective engraving, p. 48, or "Optics" data
sheet. Optionally an IC prism in slide mount can
be inserted in the Pol compensator slot (54.13).
Prisms with an additional number, e.g. D
split the beam than the D or B
therefore more sensitive for detecting fine
topological details. However, the B
used for obtaining the highest possible
resolution.
Contrast setting
Carefully move the turret round the centre
position, additionally operating the aperture
diaphragm (65.12) to optimize contrast.
The interference contrast technique gives a
relief-like and three-dimensional image of the
specimen surface.
The contrast of linear structures can be
improved even more by rotating the specimen
with the stage rotation control (48.8).
For observations in ICR colour contrast, remove
the analyser slide, rotate by 180° and push back
in with the λ engraving showing. In this position
a whole-wave compensator is effective in front
of the analyser, producing colour interference
contrast. With the analyser 360 and the ICR
module, colour contrast is only possible with the
"turnaround" polarizer L ICR with whole-wave
compensator.
To switch from interference contrast to bright-
or darkfield, turn the prism turret to position
H = brightfield, and pull out the polarizer and
analyser by one clickstop.
, B ,
1 2
prism and are
1
prism is
1
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