Guide to Using the Society's
Orion 8-inch f/6 Sky Quest XT8
If this will be your first time using a telescope like this, here are a few suggestions that may help you get started:
Using the Finders
It's a good idea to check to be sure that the finder, and/or Telrad, and the Optical Tube Assembly (OTA) are aligned. This is best done during daylight or twilight on a distant terrestrial object such as a street light or a radio tower strobe. First center your alignment target in the main scope, then adjust the finder. Should the Telrad need to be aligned, this is accomplished by adjusting the three small screws on the back of the unit. Although the Telrad may look a bit like a right-angle finder, it is not. You must place your cheek on the OTA and sight straight up along the OTA through the Telrad until you see the 3 concentric rings superimposed on the clear plastic. The on-off switch/ brightness adjustment is a small lever on the side. It's best to keep the circles as dim as possible when location objects in the night sky. Remember to turn the switch off when you're done for the evening. If you forget, please leave a fresh set of AA batteries for the next user.
When looking through the finder
your target, keep both eyes open. Then move the tube
the 6X image through the finder, and the 1X image of your unaided eye,
merge in your brain.
At the Eyepiece
Use your lowest power to locate your object, then switch to the higher power if more detail is needed. Keep in mind that not only are you magnifying the apparent size of the object you're observing, but also the apparent rotation of the Earth. You'll no doubt quickly notice that fewer tracking corrections are needed with the lower power.
You can't find your object in the
it's not in focus and you can't focus until you've located your object
in the eyepiece. Catch 22? You bet. But here's a
to limit this experience to a one time event. Using the
or a bright planet (NOT the Sun), center the object and focus.
an extreme case, you can actually remove the eyepiece and scan until
find the out-of-focus image through the focuser. Now, center this
image, insert you lowest power eyepiece and focus with the eyepiece in
place.) Now that you've achieved focus, normally with your lower
power eyepiece, use a Sharpie pen to circumscribe the focuser's draw
where it meets the focuser body. (If your other eyepiece reaches
focus at a substantially different point, you may want to mark the draw
tube there as well, with a different color or dashed
Then, on your next observing session, you will be able to fix the
focus before inserting the eyepiece. This is easier to do than to
The configuration of this scope often
observer's eye quite close to the ground. One solution is to use
a sturdy box or table to sit the scope's rocker box on. A box of
three different dimensions, for example: 12"x18"x24", would allow some
flexibility for seated or standing observing for kids and adults.
Another solution is to put down a tarp (6ft. X 8ft. or so), with the
placed on top. This has the dual advantage of keeping the knees
your pants clean and dry and well as making it easier to find dropped
filters, screws, etc.