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What are Rich Field Telescopes (RFT)?

These are low power telescopes with immense fields of view. They offer some of the advantages of binoculars where large areas of the sky may be scan through them. Technically they are compact scopes with very short focal lengths. Usual around f5 and shorter. This accounts for there low power, for power is obtained by dividingPhoto by Joe Mize, Star Fields Obsevatory the focal length of the scope with that of the eyepiece.

Of course very large apertures scopes can also have these "fast" ratios and quite often do. The term "fast" comes from photography where a fast lens offers brighter images. These are always the most expenses because they are the hardest to make.

Fast scopes or RFT's are becoming quite popular because of there large views and bright images. But most of all for there large apertures in manageable sizes. In larger instruments the term "large field of view" is relative to what it would be if it had a normal f ratio. Therefore these large aperture scopes will still have higher magnifications then smaller scopes.

To take advantage of true Rich Fields you most have a small compact scope with apertures of only 3 to 6 inches. These can be hand held or mounted for convenience They are very portable and easy to use. Views of the Milky Way are breath taking. Often the observer feels as if they are  floating in space. For general sky gazing these are the most fun and are usually the best choice for kids.

This is the scope of choice for discovering new objects as well. Many times they are referred to as comet catchers. When searching out the skies these scopes allow for sweeping large areas for finding those needles in the haystack.

Binoculars | Small Refractor | What you can see through a small inexpensive instrument


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