Celestron 44108 Mode D'emploi page 8

To change the range of working distance of the stage (4) you need to adjust the limit stop knob. Unlock the limit stop knob
by pushing it counterclockwise. Move the stage upward or downward to the desired position. Then lock the limit-stop
knob by turning it clockwise– see Figure 1f. You will adjust the limit stop knob to prevent an objective lens from hitting
the specimen you are viewing.
Adjusting the Lighting
Specimens of different size, thickness, and color variations will require different levels of illumination. There are three
ways to change the amount of illumination when viewing a specimen; adjusting the brightness control on the on/off switch
(14), adjusting the Abbe condenser (Figure 1b) and adjusting the iris diaphragm (see Figure 1b):
1. When viewing a specimen that is not transparent or dark in color you may need to increase the amount of light to
resolve certain features or details. This is best done by simply increasing the brightness of the illuminator by
rotating the brightness control on the on/off switch (14) all the way to its highest setting.
2. When viewing with lower power (4x and 10x) objective lenses you will need to lower the condenser lens in order to
spread the light over the larger field of view. To change the position of the condenser, simply rotate the silver center
portion of the Iris diaphragm (1b) clockwise until the beam of light spreads wide enough to illuminate the entire field
of view when viewing.
3. As you lower the condenser to spread out the light or change to a higher power objective lens, your image will
appear dimmer. Instead of increasing the light intensity of the illuminator (which may "wash out" fine detail of the
specimen you are viewing), open the aperture of the iris diaphragm to let in more light. Opening and closing the
diaphragm (with its lever) will give a relief view of the specimen and allow you to change the depth of field of the
specimen being viewed.
Using Filters
To bring out different levels of detail, experiment with changing the color of the back lighting of the specimen. To change
the lighting color, place the blue filter, the green filter, or the yellow filter into the filter holder which is on the bottom of
the iris diaphragm. Push the small lever on the bottom part of the iris diaphragm counterclockwise and you will be able to
see the holder. Drop a filter into the holder and rotate the filter holder back under the iris. You may need to
refocus by adjusting the fine focus knob (13) slightly for best viewing. You should experiment with each of the
colors to see the results. See Figure 1g.
Replacing the Illuminator Bulb
1. Make sure the power is off and then carefully lay the microscope on one side.
2. On the bottom of the microscope, locate and unlock (counterclockwise) the knurled knob that holds the bulb
compartment. See figure 1h.
3. Remove the knurled knob with the bulb and bulb socket. See Figure 1i.
4. Remove the old bulb from its socket but make sure beforehand that the bulb has cooled down before touching it.
5. Install the new bulb by pressing the prongs lightly into the socket.
6. Replace the bulb and bulb holder back into the base (15) by lining up the tabs and then turn clockwise to lock the
knob.
Figure 1h
Figure 1g
Figure 1i
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Filter Holder