Meade DSX Series instruction manual Too Much Power?, Location of telescope eyepiece

Fig. 14: Location of telescope eyepiece.

Your telescope comes supplied with a low-powered 26mm eyepiece which gives a wide, comfortable field of view with high image resolution.

Low power eyepieces offer a wide field of view, bright, high-contrast images, and eye relief during long observing sessions. To find an object with a telescope, always start with a lower power eyepiece such as a 26mm. When the object is located and centered in the eyepiece, you may wish to switch to a higher power eyepiece to enlarge the image as much as practical for prevailing seeing conditions.

NOTE: Viewing conditions vary widely from night-to-night and site-to-site. Turbulence in the air, even on an apparently clear night, can distort images. If an image appears fuzzy and ill-defined, back off to a lower power eyepiece for a more well-resolved image.

The power, or magnification of a telescope is determined by the focal length of the telescope 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, you may wish to use a 26mm eyepiece with the DSX-125. Look up the focal length of the DSX-125 under "Specifications: DSX-125," page 39. The focal length is listed as 1900mm.

Telescope focal length divided by Eyepiece focal length = Eyepiece power

1900 26 = 73

The eyepiece power, or magnification is therefore 73X (approximately).

DSX 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 beginning 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 well-resolved image is far superior to one that is larger, but dim and poorly resolved (see below). Powers above 200X should be employed only under the steadiest atmospheric conditions.

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 DSX telescopes. See OPTIONAL ACCESSORIES, page 37.

Fig. 15a & 15b: Jupiter; example of too much magnification.

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