3
Retractable Dew Shield
The dew shield of the EON 115mm and 130mm is retractable,
allowing the telescope to become more compact for storage.
To extend the dew shield, simply grasp and slide it out until it
is fully extended.
2.5" Dual-Speed Crayford Focuser
Focusing the EON is truly a joy, thanks to the all-machined,
extra-large 2.5" Rack and Pinion focuser (
Figure 2). It provides
exceptionally smooth, backlash-free focus motion and excel-
lent rigidity for holding heavy imaging trains without flexure or
slippage. The 2.5"-diameter drawtube ensures that even full-
frame imaging sensors will have a generously large fully illumi-
nated field. A drawtube tension knob is located on the under-
side of the focuser (
Figure 2B).
The dual-speed (10:1) focusing mechanism will keep your tar-
get object crisp and sharp. For quick focusing, the two large
focus knobs provide a coarse focus. For more precise focus-
ing, as needed for applications such as high-power planetary
observing and imaging with a CCD or digital camera, the
smaller focus knob on the right side (
Figure 2A) offers an 10:1
fine focus adjustment (~10 turns of the fine focus knob equal 1
turn of the coarse focus knob).
If you find that the focus motion feels too stiff or if, on the con-
trary, the drawtube slips easily under the weight of your eye-
piece or camera, you can make adjustments to the focuser
tension with the focuser tension thumbscrew located on the
bottom side of the focuser (
Figure 2B). Adjust this thumbscrew
until the focuser motion feels smooth and the drawtube holds
in place under load when you have obtained focus. It may
be necessary to make adjustments when the weight of your
accessories changes significantly.
Engraved Millimeter Scale on Focuser Drawtube
The drawtube of the EON's focuser features a laser-engraved
millimeter scale on top, which aids in providing repeatable
focus. When precise focus is achieved, noting the value on the
scale where the drawtube meets the focuser housing will allow
you to return to approximately the same point, such as when
focusing the same camera in subsequent imaging sessions.
Using the scale can save time compared to finding the focus-
ing point “from scratch.”
Focuser Rotation
The focuser on the EON 115mm and 130mm features a rotat-
able component. The entire focuser can be rotated just behind
the collar where the focuser attaches to the optical tube (see
Figure 2A). To rotate the focuser, loosen the rotation lock
thumbscrew (
Figure 2A) a turn or so counterclockwise. Gently
rotate the focuser to the desired orientation, then lock it in
place by turning the lock thumbscrew clockwise. If you find the
focuser is difficult to rotate, you may have to very slightly loos-
en the three rotation tensioning setscrews around the focuser
with a flat head screwdriver. If, on the other hand, you feel too
much “play” in the focuser when the thumbscrew is loosened,
you may need to tighten these setscrews a bit.
NOTE: If you do not plan to use the rotation interface, we
recommend tightening down the adjacent three setscrews
as well as the thumbscrew lock for the most secure flex-
free optical tube.
Finder Scope Dovetail Shoe
The EON’s focuser is equipped with a dovetail finder scope
shoe that allows attachment of an optional Orion finder scope,
reflex sight, mini guide scope, or the Orion Dual Finder Scope
bracket (
Figure 2A).
Using 1.25" and 2" Accessories
Your EON refractor can accommodate both 1.25" and 2"
accessories, including just about any eyepiece, diagonal, or
camera. The focuser has a 2" accessory collar attached to the
drawtube. This collar features a non-marring rotating com-
pression-style system and a thumbscrew for added security
when attaching a diagonal or other 2" accessory. The included
A.
B.
Figure 2.
The 2.5" Rack and Pinion focuser used on both
the EON 115 and 130
A) Top side, B) bottom side
Coarse
focus
knob
Fine focus
knob
2" Accessory
locking security
thumbscrew
2" Accessory
locking collar
Dovetail
finder scope
base (shoe)
Rotational
lock
thumbscrew
1.25" adapter
locking collar
Rotational
interface
Focus tensioning
thumbscrew
Rotation tensioning
setscrew (x3)
Rotation
tensioning
setscrew (x3)
