Orion XT8 manual

IN 226 Re v . E 03/05 Prov iding Ex ceptiona l Consum er Optic al Produ cts Sin ce 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 ™ IntelliScope ® XT6, XT8, XT10 #9985, #9986, #9987[...]

2 Figure 1. The SkyQuest XT8 IntelliScope Secondar y mirror holder with 4-v ane spider (not visible) Finder scope Finder scope brac ket Eyepiece F ocuser Optical tube T ensioning knob IntelliScope Controller P or t modular jack Primar y mirror cell Left side panel F oot (3) Navigation knob Retaining knob (opposite side) Computerized Object Locator [...]

3 Congratulations on your purchase of an Or ion SkyQuest XT IntelliScope Dobsonian . It is a high-perf or- mance astronomical instr ument designed to pro vide dazzling views of celestial objects and unprecedented ease of use . With the addition of the optional IntelliScope Computerized Object Locator (Controller), y ou gain the ability to locate an[...]

4 3 Plastic f eet 3 F eet attachment wood screws (length 1") 5 Encoder board mounting wood scre ws 1 Brass b ushing 1 Azimuth axis he x-head screw (length 2.25") 2 F ender washers (diameter 1") 1 He x lock nut 4 Altitude bearing cylinders 4 Altitude bearing cylinder screws (length 1.5", black) 1 V er tical stop knob 3 Flat washe[...]

5 hole, and the large hole lines up with the central hole in the baseplate . Thread an encoder board mounting screw into the predrilled star ter hole with a Phillips screwdriver and tighten until just tight. 6. Place one f ender washer (H) onto the azimuth axis scre w (I). Then push the scre w up through the hole in the ground baseplate (A).Then sl[...]

Installing the Eyepiece Rack The alumin um e yepiece rack is a standard accessor y on SkyQuest IntelliScope Dobsonians. It holds three 1.25" ey e - pieces and one 2" eyepiece (three 1.25" ey epieces on the XT6) in a conv enient place on the base, within easy reach while y ou’ re obser ving. A 1.25" bar low lens also can be hel[...]

7 SkyQuest Intelliscope Dobsonians emplo y a simple yet eff ec- tive remedy f or the fr iction problem that obviates the need for such cumbersom e co unterm easures. CorrecT ension F ricti on Optimization utiliz es a simple “disc brake” to apply the correct le vel of tension to the altitude bear ings . With the XT system, you can change ey epie[...]

8 Inserting an Eyepiece The final step in the assembly process is to inser t an ey e - piece into the telescope’ s f ocuser . First, tak e the co v er cap off the f ocuser drawtube . F or the XT8 and XT10: Loosen the thumbscre w on the 1.25" ey epiece adapter (Figure 13). Do not loosen the two thumb - scre ws on the 2" ey epi ece adapte[...]

9 Setting the Altitude T ension Level The telescope should mov e smoothly with just gentle hand pressure. While azimuth friction is not adjustab le, the altitude friction can be adjusted to the desired le v el b y turning the alti - tude tension knob (Figure 10). Note that altitude tension knob is the knob just abov e the IntelliScope Controller P [...]

10 Check the alignment by moving the telescope to another object and fixing the finder scope’ s crosshairs on the exact point y ou want to look at. Then look through the telescope’ s ey epiece to see if that point is centered in the field of view . If it is , the job is done. If not, make the necessar y adjustments until the two images match up[...]

K eep in mind that as magnification is increased, the brightness of the object being viewed will decrease; this is an inherent principle of the physics of optics and cannot be av oided. If magnification is doubled, an image appears four times dim - mer . If magnification is tripled, image br ightness is reduced by a f actor of nine! Use of 2-Inch E[...]

12 4. Alignment (Collimation) of the Optical System T o get the shar pest images, your telescope’s optical system must be in precise alignment. The process of aligning the primar y and secondar y mirrors with each other and with the mechanical axis of the telescope is called collimation. Y our telescope’ s optical system was collimated at the f[...]

13 Aligning the Secondary Mirror With the collimation cap in place, look through the hole in the cap at the secondary (diagonal) mirror . Ignore the reflections f or the time being. The secondary mirror itself should be cen - tered in the focuser drawtube , in the direction parallel to the length of the telescope. If it isn’t, as in Figure 18b, i[...]

14 T o star t, tur n the smaller thumbscrews counterclockwise a f ew tur ns each (Figure 22). Use a scre wdriver in the slots, if necessar y . Now , tr y tightening or loosening one of the larger collima - tion thumbscre ws with your fingers (Figure 23). Look into the f ocuser and see if the secondary mirror reflection has mov ed closer to the cent[...]

15 A. Selecting an Observing Site Si nce mo st as tro nom ica l ob jec ts ar e fai nt, ob ser v ing th em from dark skies will give you the best views. While some objects, such as the planets and Moon, are bright enough to see clearly ev en from light-polluted city skies, for nebulas, galaxies, and most star clusters, the less ambient light there i[...]

lower powers . It is quite common for an obser v er to own fiv e or more eyepieces to access a wide range of magnificat ions . This allo ws the obser ver to choose the best e yepiece to use depending on the object being view ed. At least to begin with, the two supplied e yepieces will suffice nicely . Whate ver you choose to vie w , alwa ys star t [...]

17 f or observing these usually faint celestial entities. For deep- sky obser ving it is impor tant that you find an obser ving site well awa y from light pollution. T ake plenty of time to let y our ey es adjust to the darkness. As you become more experi - enced and your obser ving skills get sharper , y ou will be able to f erret out more and mor[...]

18 Y our SkyQuest IntelliScope requires very little mechanical maintenance. The optical tube is steel and has a smooth painted finish that is fairly scratch-resistant. If a scratch does appear on the tube, it will not har m the telescope. Smudges on the tube or base can be wiped off with a soft cloth and a household cleaner . Cleaning Eyepiece Lens[...]

19 8. Specifications SkyQuest XT6 IntelliScope Primar y mirror :150mm diameter , parabolic, center-marked F ocal length: 1200mm F ocal ratio: f/8.0 F ocuser :Rac k-and-pinion. 1.25" e y epieces Altitude bearing diameter : 5.75" Optical tube material: Rolled steel Azimuth pad material: T eflon Altitude bearing mater ial: Ultra-high molecul[...]

20 One-Y ear Limited W arranty This Or ion SkyQuest IntelliScope Dobsonian Reflecting T elescope is warranted against defects in materials or workmanship for a period of one year from the date of purchase. This warr anty is for the benefit of the or iginal retail purchaser only . During this warranty period Or ion T elescopes & Binoculars will [...]