Proper use of the Compound Microscope 
Locate the major parts of your microscope by referring to Illustrations below.
We will be using Leitz microscopes
in this class. The instructions for correct alignment of the condenser will be applicable
to other microscopes with adjustable condensers.
Light is provided by a built in bulb which is reflected through the field iris diaphragm, the condenser, the condenser iris diaphragm, the specimen, the objective, the tube and the ocular.
There are various control knobs on the microscope which affect the light path. In addition, there are knobs for coarse and fine focus, as well as knobs to move the stage.
Locate the coarse and fine focusing
knobs
on each side of your scope. Each knob does
coarse and fine focusing. There is no
separate knob for fine focusing. You will
see how this works later. The rotation of
this knob focuses the objective onto the specimen.
Mechanical Stage
The knobs which control the mechanical stage are on the right side of the microscope as it faces you.
Condenser
The condenser aligns and focuses
light on the specimen. It has a long vertical knob
[pointing down] on its left side as you face the scope. Rotation of the small knob at its
tip, raises and lowers the condenser to achieve focus.
Swinging Lens
Directly above this at a
right angle to the
condenser adjusting knob you will find a
knob which controls a lens that can be swung in or out of place. This swinging lens is
left out for low-power illumination [i.e. 4X], and swung into the light path for
objectives of 10X or greater magnification. Failure to use this lens properly is the most common mistake that most people make. If
you fail to use this properly you will not be able to see much, especially when we use
thick
sections or whole mounts.
Centering Screws
In addition, there are two small
knobs on the
front of the condenser, set at 45o which are
used to center it.
Condenser Iris Diaphragm
Finally, there is a lever which
controls the
aperture of the Condenser Iris. This improves contrast (difference between light &
dark)
especially at intermediate and high magnifications.
Do NOT use this to increase or decrease brightness!!!
Locate all of the controls for the condenser.
REMEMBER THIS !!!!!!!!!!!!!!!!!!!!!!!!!! |
|
The Objective
focuses on the Specimen
The Condenser focuses light onto the |
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Field Diaphragm
The light source is housed in the base of the microscope. It passes through the field iris diaphragm. The size of the field diaphragm is controlled by rotating a knurled ring which is concentric with it. The field diaphragm controls the area of illumination.
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 |
Locate
the field diaphragm and its knurled ring.
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