65
If this image is not absolutely sharp: remove the
diaphragm module (see page 30) and slightly
pull out or push in the mount of the graticule (slit
on one side for screwdriver). After replacing the
module, check exact focusing and repeat the
process if necessary!
Objectives
See page 47 for detailed information on how to
use objectives. The main points are described
again below:
Objective engraving
Only use objectives with “infinite” tube length
(
∞
engraving).
∞
0.17 0 –
Note coverglass specifications (objective en-
gravings 0.17, 0 or –).
Immersions
For all immersion objectives: before focusing,
make sure that the front part of objective is not
pushed in and locked (pull out telescopically,
page 51).
Only use OIL objectives with Leica DIN/ISO
standard immersion oil. Clean with ethyl alcohol
only.
IMM objectives can be used with water,
glycerine, oil, etc.
W objectives should be used with distilled
water.
To immerse: Lower the stage or turn the
objective slightly out of the light path, apply 1 – 2
drops of immersion oil to the specimen, taking
care to avoid bubbles. Focus carefully, as the
working distance of immersion objectives is
usually extremely short. Be careful with
objectives with front locking device!
Centration
Only for p olarized light microscop es:
objective centration*
The objectives are centered by adjusting them
with two Allen keys (1.4) until the optical axis of
the objective (and thus the centre of the image)
coincides with the axis of rotation of the stage.
When the objective is properly centred, a
focused area of the specimen does not drift out
of the field of view when the stage is rotated. A
specimen point in the centre of the crosslines
therefore remains in this position for a whole
stage rotation. It is advisable to use a high-
contrast specimen full of detail for objective
centration.
Fig. 45
Survey condenser
