As living standards improve, people gradually pay attention to leisure activity, regardless of hiking, bird watching, the theatre, and stargazing activities, a good performance of the binocular telescopic can greatly expand your horizons, increase the fun of leisure, binoculars on the market everywhere, type more let a person too, there are a lot of companies are random individual, consumers without some basic knowledge, pick a casually, spent money but not get the desired effect is small, if buy the poor quality of products, not only can't let your eyes enjoy the real comfortable picture, may also cause harm to your eyesight, is really not worth the cost, so it is recommended that you here, if you want to buy a telescope applicable, high quality, it is better for basic knowledge.Here provides some reference when the choice: choose the binoculars consider choosing diameter size, ratio and the lens quality three directions.
Diameter size: (1) the objective lens (telescope toward the goal in front of the lens) size (diameter or diameter), binoculars on market in 20 mm to 70 mm is relatively common, such as the telescope as marked on the 12 of 25 x25 representative diameter is 25 mm (2.5 cm), on behalf of its 12 ratio, the larger the diameter is, the greater the volume and diameter size and the telescope set light (brightness) settlement like forces have great correlation (clarity), two 12 x 25 and 12 x50 binocular lens also is 12 times, but the latter's brightness and clarity must be higher than the former.When you consider the diameter size of binoculars, nothing more than two choices: one. If it is to watch the concert, all kinds of ball games, mountain climbing, outing travel...For the priority with convenient use, best choice of small and medium caliber (below 35 mm) models, small volume and light in weight, but inevitably will sacrifice in terms of brightness reconciliation as force.2. If it is, at night or over long distances to observe astronomical observations with high brightness, high resolution as the first
Objective: namely binocular lens in the two groups most front end and the tube, close to the target of the lens, image quality have direct relationship with the quality of the objective, most of the common product is a combination of the two lens achromatic lens, a small number of high quality binoculars with three combinations, or use the special material such as ED, fluorite lens, in order to reduce the influence of the color difference.2. The eyepiece: using a telescope, lens groups near the eyes part is called the eyepiece (left eye), typical eyepiece is made up by three pieces of optical lens, ocular vision itself about 50 degrees or so, the actual view is eyepiece field divided by the rate, if the same ratio of binoculars, want to have a larger field of vision, vision and maintain around the good image, will need more lens, the design of more complex to fix, the price is relatively improved.Prism: if only the combination of the objective lens and eyepiece telescope, saw the imaging of the up and down or so are reverse, so between the lens and eyepiece also need to light the way