Swift M3-M Use And Care Manual page 10

fine focusing knob, slowly and carefully refine the focus to clearly
observe the fine details of the specimen. Now you can turn the nosepiece
to the higher magnification micro objectives. The objectives are
parfocalled so that once the 4x objective is focused; only a slight turn of
the fine focus is required to refine the focus when changing to higher
power objectives.
Step 9: (M3-B & M3-F only) Set the diopter adjustment which is designed
to help compensate for the difference between the user's eyes. To
adjust, first bring the specimen into perfect focus by using the coaxial
focusing knobs while looking through the eyepiece with the right eye only
(close your left eye). Now, using your left eye only (close the right eye)
turn the left eye diopter only (don't touch the focus controls) to obtain a
crisply focused image. The diopter adjustment is now set and no further
adjustment will be needed until a new operator uses the scope.
Please note: A smaller diaphragm aperture (opening) increases the
contrast in the image while a larger aperture decreases the contrast.
(The diaphragm is not intended for controlling the brightness of the
illumination). A good procedure to follow in selecting the proper opening
is to start with a large aperture and reducing it until the fine detail of
the specimen is in exact focus. Using an inappropriate aperture results in
a "washing out" of the image. Care must be exercised not to reduce the
aperture too much to gain high contrast, as then the fine structure in the
image of the specimen will be destroyed. Reducing the aperture does
increase contrast and depth of focus, but it also reduces resolution and
causes diffraction. The aperture for the 10X objective will not be the
same as for the 40XRD objective, since the angle of the required light is
determined by the numerical aperture (N.A.) of the objective. The
proper aperture of the diaphragm can be easily achieved after minimal
experience with the microscope.
Macroscopic Operation
Step 1: Loosen the stage ring thumbscrew on the right side of the stage
ring. Insert the specimen cup or the black/white contrast plate into the
stage ring. The specimen cup is designed to be rotated while viewing a
specimen so the thumbscrew does not need to be tightened. If the
contrast plate is being used, tighten the thumbscrew to secure it in
place.
Step 2: Loosen the stage position thumbscrew on the right side of the
stage to move the stage assembly to the suggested middle position for
specimen cup use (indicated by 1 red dot) or the lowest position for
contrast plate use (indicated by 2 red dots). The red dot below the stage
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