8. Operation
For lockable immersion objectives:
• Lock these by pushing the front part upwards
until it stops (approx. 2 mm).
• Then, after a gentle turning motion to the
right, the objective is locked (Fig. 63).
For objectives with corrective mounts:
• Turn the knurled ring to adjust the objective to
the thickness of the cover glass.
Fig. 63a Immersion objective, released
56
Objective centering *
(DM4500 P)
!
Caution:
When changing the objective, the centering key
must no longer be in the corresponding open-
ings.
When centering the objectives (Fig. 64, 65), use
two hexagon wrenches to move the objectives
so that the optical axis of the objective (and,
therefore, the center of the image) is aligned
with the axis of rotation of the objective stage.
If the objectives are centered correctly, a pro-
grammed specimen position will not drift out of
the field of vision when the stage is turned.
Therefore, a specimen point located inside the
center of the cross-hairs does not change its
position when the stage is rotated a full turn.
When centering objectives, it is best to use a
detailed, high-contrast specimen.
Fig. 63b Immersion objective, locked