Orion XT4.5 manual

IN 164 Rev .A Providing Exceptional Consumer Optical Products Since 1975 Customer Support (800) 676-1343 E-mail: support@telescope.com Corporate Offices (831) 763-7000 P .O. Box 1815, Santa Cruz, CA 95061 INSTRUCTION MANUAL Orion ® SkyQuest ™ XT4.5 Dobsonian Reflector #9804[...]

2 W elcome to an e xciting ne w world of adventure! Y our SkyQuest XT4.5 Dobsonian is a high-quality opti- cal instrument designed to bring you dazzling views of the outer reaches of our universe. Easy enough for kids to use, and portable enough for anyone to carry , the SkyQuest XT4.5 will provide fun and entertain- ment for the entire family . Wh[...]

3 1. Unpacking The telescope will arrive in two boxes, one containing the optical tube assembly and accessories, the other containing the unassembled Dobsonian base. Be careful unpacking the boxes. We recommend keeping the original shipping con- tainers. In the event that the telescope needs to be shipped to another location, or returned to Orion f[...]

4 2. Assembly Now that you have unpacked the boxes and familiarized yourself with all the parts in front of you, it's time to begin assembly . The optics of the telescope are already installed in the tube, so most of the required assembly concerns the Dobsonian base. Assembly of the Dobsonian base Refer to Figure 2 during base assembly . The b[...]

5 Y ou can install the rack so that it can be removed, or you can install it so it is permanently attached. About halfway down the left side panel of the base you will notice two predrilled starter holes, about 4" apart. T ake the black wood screws that come packaged with the rack and thread them into the starter holes about three turns. Then [...]

T o place the finder scope in the finder scope bracket, first unthread the two black nylon screws until the screw ends are flush with the inside diameter of the bracket. Place the O-ring that comes on the base of the bracket over the body of the finder scope until it seats into the groove on the middle of the finder scope. Slide the eyepiece end (n[...]

XT4.5 during the day , before observing astronomical objects at night. This way you will not have to fumble around trying to orient yourself in the dark! Find a spot outdoors where you have plenty of room to move around the telescope, and where you have a clear view of some object or vista that is at least 1/4-mile away . It is not critical that th[...]

8 (open) end is pointing in the general direction of an object at least 1/4-mile away . Now , with your fingers, slowly rotate one of the focuser knobs until the object comes into sharp focus. Go a little bit beyond sharp focus until the image just starts to blur again, then reverse the rotation of the knob, just to make sure you ’ ve hit the exa[...]

9 25mm eyepiece, you may want to increase the magnification to get a closer view . Loosen the thumbscrew on the focuser drawtube and remove the eyepiece. Insert the 10mm eye- piece in the focuser then tighten the thumbscrew . If you were careful not to bump the telescope, the object should still be centered within the field of view . Notice that th[...]

10 Cooling the T elescope All optical instruments need time to reach “ thermal equilibri- um ” to achieve maximum stability of the lenses and mirrors, which is essential for peak performance. When moved from a warm indoor location outside to cooler air (or vice-versa), a telescope needs time to cool (or warm) to the outdoor tem- perature. The b[...]

11 Remember that objects appear to move acr oss the field of view faster at higher magnifications. This is because the field of view becomes narr ower . Eyepiece Selection By using eyepieces of varying focal lengths, it is possible to attain many magnifications with the SkyQuest XT4.5. The telescope comes with two high-quality Sirius Pl ö ssl eye-[...]

12 Io, Callisto, Europa, and Ganymede. Higher power eyepieces should bring out the cloud bands on the planet ’ s disk. SA TURN The ringed planet is a breathtaking sight when it is well positioned. The tilt angle of the rings varies over a peri- od of many years; sometimes they are seen edge-on, while at other times they are broadside and look lik[...]

ly , until the telescope is centered on the new star . Continue using stars as guideposts in this way until you are the approximate position of the object you are trying to find (Figure 15). Look in the telescope ’ s eyepiece, and the object should be somewhere within the field of view . If it ’ s not, sweep the telescope carefully around the i[...]

14 Appendix A: Collimation (Aligning the Mirrors) Collimation is the process of adjust- ing the mirrors so they are perfectly aligned with one another . Y our tele- scope ’ s optics were aligned at the factory , and should not need much adjustment unless the telescope is handled roughly . Accurate mirror alignment is important to ensure the peak [...]

15 the secondary mirror (the smallest circle, with the collimation cap “ dot ” in the center) is off-center . Y ou will fix that in the next step. Adjusting the Primary Mirror The final adjustment is made to the primary mirror . It will need adjustment if, as in Figure 16d, the secondary mirror is centered under the focuser and the reflection o[...]

16 Before cleaning with fluid and tissue, blow any loose particles off the lens with a blower bulb or compressed air . Then apply some clean- ing fluid to a tissue, never directly on the optics. Wipe the lens gently in a circular motion, then remove any excess fuild with a fresh lens tissue. Oily finerprints and smudges may be removed using this me[...]