C. Adjusting the opening on the diaphragm.
The diaphragm (8) for this series consists of a rotating disk with 6 apertures of distinct
diameters. A click marks the correct positioning in the optical path.
The function of the diaphragm is to obtain the best resolution and to provide contrast in the
image. Smaller apertures will deliver higher contrast to image, although if the aperture is too
small resolution will be poor. It is best to experiment to achieve the best resolution possible.
Suggested apertures for each objective are as follows:
OBJECTIVE
APERTURE OF IRIS
4X
The
largest
aperture.
10X
The
medium
aperture.
40X
The
smallest
aperture.
D. Changing
magnification.
1. Position the 10X objective (5) in the optical path.
2. This microscope has been parfocalised by the manufacturer, although it is possible that
small differences exist between objectives. The fine focus knob (10) can be used to readjust
the focus. For the model SFC-3A adjust using the coarse focus knob (9).
3. When changing to the 40X take care to ensure that the objective does not rub against the
slide, as damage can occur to the front lens of the objective.
Maintenance
A. Optical maintenance.
Do not attempt to disassemble any optical component.
Prior to cleaning any of the lens surfaces, remove dust particles using a fine brush, specifically for
cleaning lenses. Alternatively, use low pressure compressed air, available in shops selling
photography equipment.
1. Cleaning
the
eyepiece
a. Do not remove the eyepiece (1) or the eyepiece tube (2).
b. Only clean the outer surface, misting the lens with breath.
c. Afterwards, dry the lens with special lens paper in circular motions, from the centre
outwards. Do not clean the lenses when dry as they can be easily scratched.
2. Cleaning
the
objectives.
a. Do not remove the objectives (5) from the microscope.
b. Only clean the outer surface. Use a soft cotton cloth slightly dampened with Xylene,
afterwards dry the lens with the same cloth.
3. Cleaning
the
mirror.
Use any of the above methods mentioned for cleaning eyepiece or objectives.
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