54
Electronic focus
The controls of the electronic focus are:
– The focusing handwheels, conventionally
positioned on both sides of the microscope.
– Two keys (focus keys) for fast lowering of the
objective nosepiece and returning to the focal
plane. The keys are in a convenient position in
front of the right handwheel.
If both focus keys are pressed simultaneously,
coarse focusing is switched (SC). The coarse
focus is switched off again the moment that
the two keys are pressed simultaneously
again, or a different focusing speed is switched
with the STEP key.
– Key for switching the focusing speed (“STEP”,
S0 = 0.05
µ
m, S1 = 0.1
µ
m, S2 = 0.7
µ
m,
S3 = 1.5
µ
m) on the front of the microscope.
The micrometer values always indicate the
smallest stepwidth that can be carried out.
The electronic focus offers the user the follow-
ing advantages:
– Extremely sensitive focusing, especially for
high magnifications.
– Fine focusing selectable in 4 steps; coarse
focusing can be switched on “blind” at any
time.
The stepwidths desired by the user (corre-
sponding to gear ratio and sensitivity) are
allocated to every single objective and
automatically reset as soon as the particular
objective is used.
– Fast lowering of the objective nosepiece and
exact repositioning to the previously set focal
plane.
– Electronic parfocality of all objectives through
intelligent linking of motorized objective nose-
piece and electronic focus drive.
