Differential Interference Contrast - Leica DM2000 Operating Manual

!
Attention!
Always use the polarizer with the labeled side
facing upward, as otherwise the integrated
heat protection filter is ineffective and the
special polarizer
(discolouring!).
• Bring the polarizer and analyzer into cross po-
sition until they reach maximum darkness.
• Remove the object or find an empty area of
the specimen.
• Push the analyzer into the stand as far as
the 2nd clickstop or switch on the module.
• Remove compensators from the light path.
• Rotate the polarizer until you observe the
maximum extinction position in the eye-
piece (fig 63).
• Fix the cross position thus determined with
the clamping screw.
• If necessary:
Insert the λ or λ/4 compensator into the filter
holder integrated in the condenser holder and
rotate to the left, roughly as far as the stop.
CLP/PH condenser:
Insert the λ or λ/4 compensator in the slot on
the side of the condenser.
Condensers UCLP and UCA/P:
Rotate the condenser disk into position λ or
λ/4.
Alternative:
4x20 mm compensators can be pushed into
the compensator slot.
will become useless

9.1.6 Differential Interference Contrast

• Insert a specimen, rotate a suitable objective
into place and bring the image into focus.
• Turn the disk in the UCA/P condenser to the
brightfield position.
• If present: switch the fluorescence illuminator
into an empty position or filter system A.
• Pull the objective prism slide out of the tube
slit.
• Set the Köhler illumination exactly (→⊇p. 31).
• Remove the specimen or find an empty area of
the specimen.
• Bring the polarizer and analyzer into cross po-
sition until they reach maximum darkness, as
described at 9.1.5 Polarization.
Fig. 63
Crossing the polarizers when observing through a focusing
telescope or Bertrand lens, high-aperture Pol objective
a exactly crossed, b not exactly crossed
Pos. a cannot be set if there is strain in the condenser or
objective, Pos. b is adequate for polarization contrast.
a
9. Contrast Methods
b
53