Transmitted Light - Leica DM2000 Operating Manual

9. Contrast Methods

9.1 Transmitted Light

Objective Magnification 2.5x*
The CL/PH and CLP/PH condensers can be used
alone starting at 4x magnification.
When using a diffuser slider*, 2.5x magnification
is also possible; not when using polarization,
however.
Note:
The CL/PH and CLP/PH condensers are not used
with the Leica DM2500.
The UCL and UCLP condensers can also be used
alone starting at 4x magnification.
When using an adapter lens* (in the condenser
disk), 2.5 x magnification is also possible.
Before using the adapter lens, set Köhler illumi-
nation (→ p. 31) with the 4x or 10x objective.
Switch over to objective 2.5x, engage the lens,
open the aperture diaphragm as far as the stop
and narrow the field diaphragm.
In case of arc-shaped vignetting, center the
lens: Insert both centering keys into the con-
denser at an angle from the back and adjust un-
til the asymmetrical vignetting disappears. Re-
move the centering keys and open the field
diaphragm.
The lens can only be used up to an objective
magnification of max. 20x. Exact Köhler illumina-
tion can no longer be obtained!
The Achr.Apl.0.9 (P) condenser can be used
alone starting at 4x magnification.
With the condenser head swung out, 2.5x objec-
tive magnification is possible without a diffuse,
with the head swung in, the diffuser must be in
place (max. eyepiece field number 22).
Objective Magnifications 1.25x* and 1.6x
for Leica DM2500
The UCA/P and Achr.Apl.0.9 (P) condensers can
be used alone starting at 1.25x magnification.
The condenser head is switched off for objec-
tive magnifications from 1.25x to 5x and
switched on from 10x upward.
Use the 106z lamp housing to improve the illumi-
nation. To center the lamp, follow these steps:
(for information on the controls, see p. 36)
• Swing the condenser head in and switch over
to the 1.25x objective.
• Display the lamp filament as a square in the
visual field by focusing the collector.
• Center the image in relation to the objective.
Magnifications of 1.6x and 2.5x are also possible
with the CL/PH or CLP/PH, UCL or UCLP con-
densers if the condenser is removed completely.
The field diaphragm then takes over the function
of the aperture diaphragm.
9. Contrast Methods
49