Explore Scientific TWILIGHT Series, Руководство пользователя

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FOCUSERS
Introduction To Our Focusers
It takes more than excellent optics for your telescope to truly perform. If you want to
capture the intricacies of our Moon’s winding Hadley Rille or the spiraling arms of the
Pinwheel Galaxy, you will need to have a superior focuser in your astronomical arsenal.
The focuser is one of the most important mechanical components of your telescope
because it is the tool you use to find and hold that perfect crisp image. Although there are
differences in design, all four of our dual-speed focusers are built to meet high standards
of precision and functionality. We want to make sure you see the details you seek without
needing to make constant adjustments.
COMMON FEATURES
In addition to a shared mission to provide you the best viewing experience, each of our
focusers have some similar elements. These include:
• Fine and Coarse Focusing: On one side of each focuser you will find a stacked set of
dials. The largest of the pair controls your coarse focusing and the smaller provides
micro-focusing. Both controls are knurled so that you can grip them easily for smooth
adjustments even when you are wearing gloves.
• Locking and Tension Screws: Although they are located in different places on each
model, locking and tension screws perform vital functions on all of our focusers. To
avoid unintended adjustments, the locking screw can be gently tightened to keep the
focuser stationary once you have reached your desired focus. The tension screw(s) are
used to put pressure on the drawtube to secure it and keep it from sliding when heavier
accessories like cameras or large eyepieces are added.
• Tension Collar: At the end of each focuser, you will find a tension collar with three set
screws that are used to hold a diagonal or an eyepiece in place.
• Compression Ring Eyepiece Adapter: The purpose of this component is to allow you to
still use eyepieces/diagonals that are smaller than the diameter of the drawtube. Our
three 2” focusers include a 1.25” adapter, while our Feather Touch 3” focuser includes a
2” adapter. The adapter locks into place in the tension collar by tightening the collar’s set
screws.
STYLES OF FOCUSERS
Rack and Pinion Focuser
This focuser uses a circular gear (pinion) linked to the focus dials to move the drawtube
along a linear rack lined with teeth. As you turn the dial the gear engages with the teeth
guiding the drawtube in and out. On this 2” focuser, the locking screw is in the center
on the underside of the focuser and the two tension screws that press down to keep the
drawtube from slipping are on the top. This focuser is also rotatable, meaning that it can
be easily repositioned to change the position of the dials or to meet your specific comfort
or viewing needs. To use this feature, slightly loosen the tension screw on top of the
visual back adapter on your telescope tube that presses down on the focuser, rotate the
focuser and gently retighten the screw.