2.Loosen the Dec. lock lever and rotate the optical tube on the declination axis so that the tube is at a 90° to the right ascension axis (Figure 10). This is so you can view through the mount with the polar axis finder. Tighten the Dec. lock lever.
3.Remove the cap on the front of the equatorial mount (Figure 6). Focus the polar finder by rotating the eyepiece. Now, sight Polaris in the polar axis finder scope. If you have followed the approximate polar alignment procedure accurately, Polaris will probably be within the field of view. If not, move the tripod
4.Shine a red flashlight down the front end of the polar finder to illuminate the reticle within the field of view. Make sure the flashlight shines in at an angle, so as not to block the polar finder’s field of view. It may be helpful to have a friend hold the flashlight while you look through the polar finder. Note the constellation Cassiopeia and the Big Dipper in the reticle. They do not appear in scale, but they indicate the general positions of Cassiopeia and the Big Dipper relative to the north celestial pole (which is indicated by the cross at the center of the reticle). Rotate the reticle so the constellations depicted match their current orientation in they sky when viewed with the naked eye. To do this, release the R.A. lock lever and rotate the main telescope around the R.A. axis until the reticle is oriented with sky. For larger optical tubes, you may need to remove the tube from the mount to prevent it from bumping into the mount. Once the reticle is correctly oriented, use the right ascen- sion lock lever to secure the mount’s position.
Now use the azimuth adjustment knobs (Figure 8) and the latitude adjustment
Note: From this point on in your observing session, you should not make any further adjustments in the azimuth or the latitude of the mount, nor should you move the tripod. Doing so will undo the polar alignment. The tele- scope should be moved only about its right ascension and declination axes.
Additional Note Regarding Focusing the Polar Axis Finder Scope
The polar axis finder scope is normally focused by simply rotating the eyepiece focus ring. However, if after adjusting the focus ring you find that the image of the reticle is sharp, but the stars are out of focus, then you must adjust the focus of the polar axis finder’s objective lens. To do this, first remove the polar axis finder from the mount. Look through the polar axis finder at a star (at night) or distant object at least 1/4 mile away (during daylight). Use the eyepiece focus ring to bring the reticle into sharp focus. Now, loosen the focus lock ring
(Figure 9a) and thread the entire objective end of the finder inwards or outwards until images appear sharp.
Use of the Right Ascension and Declination Slow- Motion Control Knobs
The right ascension (R.A.) and declination (Dec.)
Note: If you have an optional motor drive attached, you will need to loosen the manual clutch on the R.A. (and Dec. for
The object should now be visible somewhere in the telescope’s finder scope. If it isn’t, use the
Tracking Celestial Objects
When you observe a celestial object through the telescope, you’ll see it drift slowly across the field of view. To keep it in the field, if your equatorial mount is polar aligned, just turn the R.A.
Optional Motor Drives for Automatic Tracking
An optional DC motor drive can be mounted on the R.A. axis of the equatorial mount to provide
Understanding the Setting Circles
The setting circles on an equatorial mount enable you to locate celestial objects by their “celestial coordinates”. Every object resides in a specific location on the “celestial sphere”. That location is denoted by two numbers: its right ascension (R.A.) and declination (Dec.). In the same way, every loca- tion on Earth can be described by its longitude and latitude. Right ascension is similar to longitude on Earth, and declina- tion is similar to latitude. The R.A. and Dec. values for celestial objects can be found in any star atlas or star catalog.
The R.A. setting circle is scaled in hours, from 1 through 24, with small marks in between representing
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