Also referred to as field glasses, binoculars telescopes are a pair of mirror-symmetrical telescopes that allow a viewer to use binocular vision to view distant objects. Since they are aligned to point in the same direction, they produce an impression of depth and at great distances, the depth perception is apparent. They are thus much better than the monocular telescopes. This three dimensional view of objects is not obstructed even when viewing close objects.
The optical design of binoculars telescopes of mounting two side by side is not a new concept. From the Galilean binoculars of the 17th century, this design was already well explored. Early binoculars telescopes had narrow fields of view and low magnifications. This construction can still be found in cheap binocular models and opera glasses. The prism binoculars model employed the Keplerian optics where the image is inverted by viewing it through the ocular, an eyepiece lens. These binoculars telescopes have wide pieces.
When purchasing binoculars telescopes, it is good to look at the optical parameters usually listed on the cover plate of the binocular. One of these parameters is the magnification. This is the ratio of focal length of the eyepiece to the focal length of the objective, sometimes expressed as diameters. A magnification of 10, for example, produces an image as if one was 10 times closer to the object. The larger the magnification ratio, the smaller the field of view. Another parameter is the objective diameter. This determines how much light is gathered to form an image and is expressed in millimeters. The field of view is a linear value either in meters or in degrees and is designed by the binoculars optical design. The exit pupil should be small to match the pupil of the eye, approximately 7mm. the eye relief distance is particularly important for those who wear glasses. Ensure that it is 2.5 centimeters or slightly more. The close focus distance is the closest the binoculars can focus and varies anywhere between 1 meter and 20 meters.
Binoculars telescopes of particular should have a low magnification when it comes to magnifying power and objective lens ratio. A magnification of 12.5 or greater is typical of binoculars telescopes. In order to offer image stability, image-stabilization technology has been designed into these binoculars. However, stabilized binoculars also tend to cost more and are much heavier compared to the non-stabilized ones. Thus, weigh the advantages and disadvantages when selecting your choice of binoculars telescopes.