Telescope Type
Telescopes come in three varieties: ,
,
and .
Each kind of telescope collects and focuses light so that it can be
magnified or recorded, but each does so differently. All perform well
when properly designed and manufactured, but each has its own special
advantage.
Catadiaoptric telescopes utilize a combination of lenses and mirrors.
Refractors incorporate lenses, and Newtonian reflectors use mirrors.
Choosing a particular telescope depends on your requirements. Before
buying, you should consider what you plan to use the telescope for now
and in the future. Many amateurs own two or more telescopes to satisfy
their varied interests.
Telescope Performance
"What is the most powerful telescope I can buy?" - That depends on
what you want to view and how you measure power.
- Power - "Power" generally refers to magnification.
When viewing the countryside, the Moon or the planets, magnification
is great. Magnification is a function of a telescope's focal length
and the focal length of the eyepiece in use (normally measured in millimeters
"mm"). But magnification is not always beneficial in astronomy. For
example, when viewing nebulae and galaxies, a lower-power, wider-field
scope, that can reveal dim objects, is more important.
- Light Grasp - "Light Grasp" is a measurement of how
much light a scope can gather at any given instant. Light grasp is a
function of the aperture of the telescope's main lens. A large aperture
telescope can reveal dimmer astronomical objects better than a high
magnification telescope can.
Another way to measure the performance of a telescope is to measure
how often it is used. Ask yourself which is more valuable, a small portable
scope that is enjoyed weekly or a giant telescope that sits in the closet
and is used maybe once a year? The right telescope for you is a balance
between magnification and the light gathering power of the optical system.
It depends on you; and how you plan to use your telescope.
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