Focusing - Nikon ECLIPSE Ei Instructions Manual

3.3

Focusing

This procedure is to operate the fine and coarse focus
knobs to raise and lower the stage so that the specimen to
be observed can be seen most clearly.
The UP and DOWN indications on the microscope base
indicate the direction in which the stage moves by rotation
of the focus knobs. For both the fine and coarse focus
knobs, turning in the UP direction raises the stage, and
turning in the DOWN direction lowers the stage.
Fine scale
One rotation of the fine focus knob moves the stage
vertically by 0.2 mm. The fine scale lines are provided at
intervals of 2 μm of stage travel.
Standard procedure

(1) Swing the 10x (or 4x) objective into the optical path.
(2) Rotate the coarse focus knob to raise the stage to its
upper limit.
Since the working distances of 4x and 10x objectives
are long, these objectives do not touch the specimen
even when the stage is raised to its upper limit
provided that the slide and coverglasses of a
standard thickness are used. (The standard
thickness for slide is 1.2 mm and that for coverglass
is 0.17 mm.)
(3) Looking into the eyepiece, slowly rotate the coarse
focus knob to lower the stage. When the specimen
image appears, take your hands off the coarse focus
knob.
When rotating the coarse focus knob while
looking into the eyepiece, be sure to rotate it in
the direction that lowers the stage.
When the focal point cannot be found
To find the focal point, rotate the movement stopper
counterclockwise to unlock the limit.
(4) Rotate the fine focus knob and precisely focus on the
image.
Chapter 3 Detailed Explanation
53
UP/DOWN indications
Left Right
Fine scale