Orion 120 EQ manual

IN 124 Rev . C 0900 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 ® Astr oV iew ™ 1 20 EQ #9026 Equatorial Refracting T elescope[...]

2 T ube rings Objectiv e lens cell Dew cap/ lens shade Right Ascension slow-motion control (not visible) Declination lock le ver Latitude adjustment T -bolts Counterweight shaft Small counterweight Large counterweight Counterweight loc k thumbscre ws “T oe sav er” retaining bolt Azimuth fine adjustment knobs T ripod leg Accessor y tra y brack e[...]

3 1. Par ts List Qty . Description 1 Optical tube assembly 1 German-type equator ial mount 1 Large counterweight 1 Small counterweight 1 Counterweight shaft 3 T r ipod Legs with mounting hardware 1 Accessor y tra y with mounting hardware 1 Accessor y tra y brac ket 2 Slow-motion control cab les 1 P olar axis finder scope 1 Plastic cov er for polar [...]

4 2. Assembly Carefully open all of the bo x es in the shipping container . Make sure all the par ts listed in Section 1 are present. Sav e the box es and packaging material. In the unlikely e vent that you need to return the telescope, you must use the original packaging. Assembling the telescope f or the first time should take about 30 minutes. N[...]

5 12. T o place the finder scope in the finder scope brac ket, first unthread the two b lack n ylon screws until the scre w ends are flush with the inside diameter of the brac k et. Place the O-ring that comes on the base of the brack et ov er the body of the finder scope until it seats into the slot on the middle of the finder scope. Slide the ey [...]

6 2. No w loosen the counterweight lock thumbscre ws and slide the weights along the shaft until the y e xactly coun- terbalance the telescope (Figure 5a) That’ s the point at which the shaft remains horizontal e ven when y ou let go with both hands (5b). 3. Retighten the counterweight loc k thumbscrews. The tele- scope is now balanced on the R.A[...]

Alignment is easiest to do in da ylight hours. First, inser t the lowest- power (25mm) e yepiece into the star diagonal. Then loosen the R.A. and Dec. loc k le vers so the telescope can be mov ed freely . P oint the main telescope at a discrete object such as the top of a telephone pole or a street sign that is at least a quar ter-mile aw a y . Mov[...]

axis out into space. Stars in the Nor ther n Hemisphere appear to re volv e around P olaris. T o find Polaris in the sky , look nor th and locate the patter n of the Big Dipper (Figure 8). The two stars at the end of the “bowl” of the Big Dipper point right to P olaris. Obser vers in the Southern Hemisphere aren’t so fortunate to hav e a br i[...]

9 2. Rotate the date circle until the “0” line on the meridian off- set scale lines up with the time meridian indicator mar k. The meridian offset scale is pr inted on the inner circum- f erence of the date circle, and is labeled “E20” to “W20”. The time meridian indicator mar k is an engra ved line on the e xterior of the polar finder?[...]

10 Remember , accurate polar alignment is not needed for casu- al visual obser ving. Most of the time, appro ximate polar alignment, as outlined pre viously , will suffice. T racking Celestial Objects When you observe a celestial object through the telescope , you’ll see it drift slowly across the field of vie w . T o keep it in the field, if you[...]

11 c. d. Figure 10. This illustration shows the telescope pointed in the f our cardinal directions: (a) nor th, (b) south, (c) east, (d) west. Note that the tripod and mount hav e not been mov ed; only the telescope tube has been mov ed on the R.A. and Dec. ax es. a. b. Figure 10 illustrates how the telescope will look when pointed at the f our car[...]

sar y , use the R.A. and Dec. slow-motion controls to re-position the object within the field-of-view of the main telescope’ s ey epiece. Focusing the T elescope Practice f ocusing the telescope in the daytime bef ore using it f or the first time at night. Star t by turning the focus knob until the f ocuser drawtube is near the center of its adju[...]

13 lem that plagues refractor-type telescopes, since light passes through both air and glass to f orm an image. Most astronomical objects emit a spectrum compr ised of many diff erent wav e- lengths of light, so each wa v elength will be bent by a slightly diff erent amount when passing through a lens. This results in each color of light reaching p[...]

The f amous “Double-Doub le” in the constellation Lyra and the gorgeous two-color doub le star Albireo in Cygnus are f av or ites. Def ocusing the image of a star slightly can help br ing out its color . D. Deep-Sky Objects Under dark skies, you can observe a wealth of f ascinating deep-sky objects, including gaseous neb ulas, open and glob- ul[...]

15 Deep-sky objects are quite f aint, and typically require e xpo- sures on the order of 10 minutes. T o hold the camera’ s shutter open this long, you will need a loc king shutter release cab le (#5231). Set the camera’ s shutter to the “B” (bulb) setting. Depress the locking shutter release cab le and loc k it. Y ou are now e xposing your[...]

Orion T elescopes & Binoculars Post Office Box 1815, Santa Cruz, CA 95061 Customer Support Help Line (800) 676-1343 • Day or Evening One-Y ear Limited W arranty This Orion AstroView 120 Equatorial refractor is warr anted against defects in materials or work- manship f or a period of one year from the date of purchase. This w arranty is f or t[...]