![](/images/new-backgrounds/1123524/12352429x1.webp)
Note: Seeing conditions vary widely from
Turbulence in the air, even on an apparently clear night, can distort images. If an image appears fuzzy and
(see Fig. 15a and 15b below).
Note: For a list of magnifi- cation ratings of the eye- pieces available for the
Low power eyepieces offer a wide field of view, bright,
The power, or magnification of a telescope is determined by the focal length of the tel- escope and the focal length of the eyepiece being used. To calculate eyepiece power, divide the telescope's focal length by the eyepiece's focal length. For example, a 26mm eyepiece is supplied with the
Telescope Focal Length ÷ Eyepiece Focal Length = | Magnification (Power) | |
Telescope Focal Length | = | 812mm |
Eyepiece Focal Length | = | 26mm |
812 ÷ 26 | = | 31 |
The eyepiece power, or magnification is therefore 31X (approximately).
Observing by Moving the Telescope Manually
After the telescope is assembled and balanced as described previously, you are ready to begin manual observations. View
■When you wish to locate an object to observe, first loosen the telescope’s R.A. lock (33, Fig. 1d) and Dec. lock (17, Fig. 1d). The telescope can now turn freely on its axes. Unlock each axis separately and practice moving your telescope. Then practice with two unlocked axes at the same time. It is very important to practice this step to understand how your telescope moves, as the movement of an equatorial mount is not intuitive.
■Use the aligned viewfinder to
■A telescope’s eyepiece magnifies the image formed by the telescope’s main optics. Each eyepiece has a focal length, expressed in millimeters, or “mm.” The smaller the focal length, the higher the magnification. For example, an eyepiece with a focal length of 9mm has a higher magnification than an eyepiece with a focal length of 26mm.
Fig. 15a & 15b: Jupiter; examples of the right amount of magnification and too much magnification.
LXD75 TIPS
Too Much Power?
Can you ever have too much power? If the type of power you’re referring to is eyepiece magnification, yes, you can! The most common mistake of the begin- ning observer is to “overpower” a telescope by using high magnifications which the telescope’s aperture and atmospheric conditions cannot reasonably support. Keep in mind that a smaller, but bright and
Autostar can calculate the best eyepiece for you to use. Try out the “Eyepiece Calc” feature in the Utilities menu.
Most observers should have three or four additional eyepieces to achieve the full range of reasonable magnifications possible with the
15