Using your Dobsonian
Your Explore Scientific Dobsonian is a precision optical instrument and should be used with care. Try to avoid exposing your
telescope to vibrations because this may cause the telescope to lose collimation.
Aligning the viewfinder
The red dot that is used by the finder scope is not readily visible during the day. For this reason you should align the finder scope
once it is dark.
To do this:
1. Insert an eyepiece with low magnification into the focuser of the telescope and make sure that the red dot finder scope has
loaded batteries and is switched on.
2. Look through the eyepiece and center an object that is easy to find at a minimum distance of more than 800m, like a street
lamp.
3. Look through the red dot finder and move your head until you see the red dot of light that is projected onto the glass window.
Adjust the finder with the two screws until the red dot is on top of the object that is centered in the telescope’s eyepiece. You can
fine-tune the finder collimation on a celestial object, like a bright star or a crater on the moon, by following the same procedure.
Focuser
The focuser of the Explore Scientific truss Dobsonian is equipped with a 10:1 reduction (figure 12).
Figure 9
This reduction makes fine focusing easy. You can lock the focuser by using the locking screws on the upper side of the focuser.
Tighten the screws until you feel some resistance – the focuser draw tube is now locked and will not move.
Notice:
Never try to force the focuser beyond the stops. Do not turn the focuser knobs while the focuser is locked. Turning the
focuser knobs while the focuser is locked may result in damage to the focuser.
Summary of Contents for Truss Tube Dobsonian Series
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