Leica DMLB Bedienungsanleitung Seite 57

Diaphragm settings
Open the field diaphragm (39.6) until the field
of view is just illuminated. Stopping down may
improve the contrast and be gentler to sensitive
fluorescence specimens. Centration: Put the
two centering keys (2.4) into the two holes
(39.5) and turn until the diaphragm is in the
centre position. Max. field of view: with
fluorescence illuminator LRF 4/22 = 22, with
additional optics: 25.
With universal illuminator LU or LUP: 25.
Aperture diaphragm (39.8): For fluorescence
open fully, for incident light brightfield,
polarization and interference contrast ICR stop
down to the desired contrast. To centre (does
not apply for fluorescence): Use a flat, well-
reflecting specimen, if necessary a glass plate
(specimen slide). Use the BF or POL reflector
and focus. Pull out the eyepiece so that the
aperture diaphragm (39.8) can be seen in the
eyepiece tube. Alternatively, use the auxiliary
telescope (30.1) or a Bertrand lens. Push in the
two centering keys (2.4, 39.7) and turn until the
aperture diaphragm is in the centre position.
Mirror housing for 2 lamp-housings
For alternate use of two lamps, the manually
switchable mirror
interposed between the incident light illuminator
and the two lamphousings.
housing 106 can
Protective filter*
When using gas discharge lamps for polarized
light, it is advisable to slot a protective filter (not
illustrated) into the front of lamphousing 106 z to
avoid damaging the incident light polarizer (POL
filter system).
Possible errors
Weak fluorescence, weak image intensity due
to:
Incorrectly stored, too old or faded specimens,
fast specimen fading (e.g. for FITC); inspecific
filter combination, numerical aperture of
objectives too low, eyepiece magnification too
high, spent lamp, room too bright. Trinocular
tube: wrong
secondary light due to reflection at the
condenser.
Low contrast image due to:
Excitation bandwidth too great, inspecific
staining, fluorescing mounting medium, auto-
fluorescence of the objective or immersion oil.
Dirty glass surfaces.
be
beamsplitter setting (45.4),
57