Telescope

 

A telescope is an optical instrument that uses lenses or mirrors and other optical devices to observe distant objects. 

It uses the light refracted through the lens or reflected by the concave mirror to make it into a small hole and converge to image, 

and then through a magnifying eyepiece and be seen, also known as the "thousand mile mirror".

    The first function of a telescope is to magnify the Angle of distant objects so that the human eye can see details at smaller angular distances. 

The second function of the telescope is to beam light collected by the objective lens, much thicker than the diameter of the pupil (up to 8mm),

 into the human eye, allowing the observer to see faint objects that would otherwise be invisible. In 1608, Hans Liebosch, 

a Dutch optician, accidentally discovered that he could see distant objects with two lenses, and was inspired to build the first telescope in human history. 

In 1609, Galileo Galilei, a Florentine, Italy, invented the 40-fold bifocal telescope, which was the first practical telescope to be put into scientific use.

Commonly used binoculars for the purpose of reducing the volume and flip down like, 

need to increase the prism system, prism system according to the shape if type can be divided into different don't han prism system (i.e., schmidt - don't han roof prism system) and Paul prism system (also called a porro prism system), the principle and application of two systems is similar.

   Suggestions for buying:Telescope

   Personal use of small handheld telescopes should not be used too large magnification, generally 3 to 12 times is appropriate, multiple is too large, imaging clarity will become poor, while the jitter is serious, more than 12 times the telescope is generally used tripod to be fixed.