Explore Scientific TWILIGHT Series, Manual

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8
AR DOUBLET SERIES
and/or any heavy attachments like cameras or large eyepieces are installed. You may
need to make adjustments for cone error if you are using a German equatorial mount.
Cone error occurs when the polar axis of your mount and the center of your telescope’s
optical axis are not aiming at the same point in the sky. To check for cone error, you
will need to first line your mount up with a fairly fixed point in the sky like Polaris or a
stationary terrestrial target that will be far enough away to see well in your telescope.
Mount your telescope and see if it is centered on the same target. If it is not, you will need
to take the scope off of the mount and slightly tilt the telescope tube away from or toward
the saddle plate by threading the adjusting screws in or out. These screws flank a central
locking screw on each end of the saddle plate. The process will take some trial and error
before the perfect adjustments are found. Please note that when the final adjustments
are made, the center locking screw must have enough engagement with the threads of
the cradle ring to make sure that the saddle plate stays connected.
FINDER SCOPE
Please note: On our 102mm AR Doublet Achromatic Refractor, you will need to install
the finder scope before you put on the cradle ring assembly. On all of our other telescope
models, the finder scope can be installed after the cradle rings are in position.
Each scope in our AR Doublet Series comes with a non-illuminated straight finder
scope: This classic reverse-view finder scope has a simple crosshair that can be centered
on your target. The first step in mounting your finder scope to your telescope is to slide it
into the finder scope bracket, which has two rings to hold your finder scope in place. Each
of these rings has three adjusting screws. If your finder scope is not already installed
in the bracket, loosen each of the adjusting screws until you have opened up the full
inside diameter of the rings. Slide the finder scope into place and gently tighten all of
the adjusting screws until your finder scope is secure. The bracket has a dovetail base
that slides easily into the mounting assembly that is already attached to the optical tube
assembly (OTA). Once it is installed in the base, secure it by tightening the two large,
heavy-duty plastic screws. For information on aligning your finder scope and telescope,
please refer to the finder scopes pamphlet.
Defocused and focused
out-of-collimation
star images (1 and 2
Defocused and focused
properly collmated
star images (3 and 4)
Figure 1
1
3
2
4