Leica DM2700 M, Instructions Manual

Page: 37 / 156

37
7. Startup
7.2.2 Incident Light
The condenser module is pre-centered at the
factory.
However, depending on how the stand is trans-
ported and assembled, it may be necessary to re-
center the condenser in some cases. Therefore,
check the diaphragm centering.
The following procedure is provided for incident
light-bright fi eld illumination.
• Select an objective with moderate magnifi ca-
tion (10x-20x).
• Activate the incident light axis if necessary by
pushing the toggle button (28.5).
• Switch on the BF (= brightfi eld) or Smith refl ec-
tor.
• Place a specimen on the stage.
• Bring the specimen into focus and adjust the
light intensity.
Adjusting the Aperture Diaphragm
• Use a fl at specimen with good refl ective prop-
erties, and a glass plate (specimen carrier) if
necessary.
• Remove one ocular (the right one, for exam-
ple). Alternatively, you can also use a focusing
telescope or Bertrand lens.
• Close the aperture diaphragm using the crank
(30b.1) until the edge of the diaphragm appears
in the exit pupil of the objective (aperture dia-
phragm plane).
• If the image does not appear in the middle of
the fi eld of view, the aperture diaphragm must
be moved into the exit pupil using the center-
ing screws (30c.1).
• Open the aperture diaphragm until the color
ring of the objective and the color marking of
the aperture diaphragm (30b.2) match.
Fig. 30b Köhler Illumination
1 Aperture diaphragm adjustment
2 Color coding
Fig. 30c Aperture diaphragm centering
1 Centering keys
2 Centering screws
1
2
1 2