Leica DM2700 M, Инструкция по эксплуатации

Страница: 61 / 156

61
9. Contrast Methods
!
Caution!
Always use the polarizer with the labeled side
facing upward , as otherwise the integrated
heat protection fi lter is ineffective and the spe-
cial polarizer will become useless (discolor-
ing!).
• Bring the polarizer and analyzer into cross po-
sition until they reach maximum darkness.
• Remove the object or fi nd an empty area of
the specimen.
• Push the analyzer into the stand as far as the
2nd click stop or switch on the module.
• Remove compensators from the light path.
• Rotate the polarizer until you observe the
maximum extinction position in the eyepiece
(Fig. 63).
• Fix the cross position thus determined with
the clamping screw.
• If necessary:
Insert
the
λ
- or
λ
/4 compensator into the fi lter
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.
9.2.6 Differential Interference Contrast ICT
• 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
brightfi eld position.
• If present: switch the incident light illuminator
into an empty position or fi lter system A.
• Pull the objective prism slide out of the tube
slit.
• Set the Köhler illumination exactly (
→
p. 35).
• Remove the specimen or fi nd an empty area of
the specimen.
• Bring the polarizer and analyzer into cross po-
sition until they reach maximum darkness, as
described at 9.2.5 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 ob-
jective, Pos. b is adequate for ICT and polarization contrast.