Tip & How-To about Optics
Even though we warned you not to do this, you bought one anyway! Beginners should never buy an EQ telescope mount as their first telescope. It's too late now; so I guess we will need to teach you how to use it!
Equatorial mounts move in a way that seems not to very intuitive. Unlike the easy Alt AZ mount which moves up and down and left and right, the EQ mounted telescope seems to move in TWO dissimilar directions at the same time.
Additionally you must first polar align the mount on the North star Polaris before you can use it. SEE! we told you not to buy it!
Here are the steps to roughly polar align the telescope so you can use it. If it is motorized the single Right Ascension motor will keep the sky object inside the eyepiece for long periods of time. If you do not have a Right Ascension motor, the slow motion RA knob can be slowly turned to keep the sky object centered in the eyepiece.
Begin by leveling the mount and tripod. Move the entire mount and tripod so it is pointing roughly to North, as close as possible using the steps below or a compass. Don't forget to adjust for your magnetic deviation. My location's compass reading is about 5 degrees away from true North. This is called magnetic deviation. You can find your location's deviation on the internet. Then proceed with the steps below.
First, adjust the Declination to the latitude for your observing site. Declination is the angle that the scope is pointing UP, and it's the same as your latitude. For example Dallas, Texas is about 32 degrees North latitude, adjust the scope so the small indicator reads 32 degrees. By the way, the North star in Dallas, TX is about 32 degrees above the horizon. Your latitude matches the elevation of Polaris (the North star) above the horizon.
Second, either look through the polar alignment scope buried in the axis of the telescope mount, or look along side the axis, and get the star Polaris lined up in the cross-hair of the polar alignment scope, or as best you can by looking along the side of the mount axis, or lining it up using your compass.. This will put the scope to within about 3/4 of 1 degree of the TRUE North celestial sphere. This is good enough for VISUAL observation, but NOT good enough to do astro-photography..
Adjust the DECLINATION up or down, and move the entire mount left or right until you can see Polaris as indicated above, or it is lined up as close as possible.
Now you are roughly polar aligned. Now you can move the tube around by loosening the Right Ascension lock, and or the Declination lock until your sky object appears in the small finder scope mounted on top of the main telescope tube.(DO NOT MOVE THE MOUNT, and the counter weight should never be higher than the telescope tube) Lock down the scope in both axis and use the fine adjustment RA and DEC knobs to center the target. Again, DO NOT move the mount or tripod. The mount should still be pointing at Polaris.
This web site illustrates this procedure:
also this web site
You should be able to keep an object within the field of view of the eyepiece by slowing turning the Right Ascension slow motion control knob-------- IF you are actually accurately polar aligned. Small adjustments may also be needed with the DEC slow motion knob since you are not exactly polar aligned using this rough alignment technique.
However it can be used successfully for visual observation. Your scope will now track the motion of the stars as they move across the sky.
Hope that helps you!
Posted by Joe... on
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