Leica DM4000B User Manual

54

• The microscope automatically selects the

correct light ring in the condenser.

• When selecting the phase contrast method,

the aperture diaphragm is opened completely
and may not be adjusted. To avoid errors in
operation, the function keys for setting the ap-
erture diaphragm (AP) are locked.

• Switch to the transmitted light axis (TL) by

pushing the TL/IL button.

• Select the DF (dark field) contrast method.

Do so by pressing the DF variable key.
Alternatively: Press the CHANGE TL
 variable key.
(For key occupation please see “Identification
Sheet”.)
The display indicates DF.
The dark field ring (dark field stop) is set au-
tomatically.

• Insert a transmitted light specimen.

• Rotate an appropriate objective into place.

• Bring the image into focus using the focus dial

and set the brightness using the INT function
key.

• The maximum objective aperture which may

be used for dark field is 0.75. All objectives
with greater aperture are automatically
blocked for this procedure ("DF" flashes in the
display).

• The microscope automatically selects the

correct light ring in the condenser.

• When selecting the dark field method, the

aperture diaphragm is opened completely and
may not be adjusted. To avoid errors in opera-
tion, the function keys for setting the aperture
diaphragm (AP) are locked.

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