Introduction
The use of a binocular will help you expand the mind by allowing you to observe an object or a distant scene, as if they were located very close to the eye.
There are very few activities that could not be made more enjoyable through the use of a binocular. For sports, traveling, hunting, nature watching, hiking, boat, theater or concert hall, a binocular will give you a better view of the world.
Binocular classification
Each binocular model is identified by a numerical reference such as 7x35, 10x50, etc. The first number represents the power or magnification of the binoculars, and the second gives the diameter of the lens in millimeters. So a '10x50' binocular has 10x magnification and a 50mm diameter lens.
Magnification
By magnification we mean the level of increase of the image seen by the binoculars relative to that seen with the naked eye. A 7x binocular increases image by 7 times the actual size, while a 10x binocular gives 10x magnification.
Magnification can also be considered as an indication of how close the subject appears when seen through the binoculars. For example, using a 10x binocular, an object that is 100 meters away will appear to be located at a distance of 10 meters.
Lens diameter
The light collection capacity of a binocular is determined by the diameter of the lens. Binoculars with a large diameter lens (over 50mm) are designed for use in low light conditions and astronomy.
Binoculars with a small diameter lens (less than 30mm) are excellent for use in strong light, while binoculars with lens diameters in the range of 30 to 50mm offer a good fit between brightness and clutter.
Field of view
The field of view is the extent of the area seen through the binoculars. It is indicated either in angular measurement or in feet or meters at a distance of 1000 yards or 1000 meters respectively. That is, a binocular with a 358-foot or 119-meter field of view will allow you to see an area of 358 feet or 119 meters wide at a distance of 1000 yards or 1000 meters, respectively. The field of view is proportionally larger at larger distances and shorter at shorter distances.
The larger the magnification, the smaller the field of view. It follows that if you choose a binocular with high power magnification, you will have to be willing to accept a field of vision that is smaller than that obtained with a less powerful binocular.
Optical treatment
It is a well-known optical phenomenon that, under normal conditions, there will be a loss of more than 5% of the light that passes through an air-glass contact surface. An optical instrument such as a binocular that contains many air-glass contact surfaces must therefore fail to transmit to the eyes a significant portion of the light it receives. The lens surface treatment eliminates this loss and returns the light to the transmitted beam. Treatment has two obvious advantages:
(1) The image or field of vision is considerably lighter, due to the increased light transmitted
(2) The contrast and sharpness are improved by virtually eliminating unwanted rays reflected back and forth between the various surfaces of the lenses.
Focusing
The inter-pupillary distance of the eyes varies in the range of 55 to 70 millimeters; setting the binocular to match your own interpupillary distance is done by rotating the two goggles on the common hinge, increasing or decreasing the spacing of the eyepieces until the two circular fields of view merge into one only. At this point the indication of the scale should be noted, so that the adjustment can be made more easily during future use. There are two types of binoculars:
(1) Central focus mechanism
(2) Individual Focusing Mechanism
The CENTER FOCUS system uses a caster mounted between the binoculars to control the movement of the eye sets during focusing.
The INDIVIDUAL FOCUS SYSTEM: There is no central wheel. Each eyepiece must be developed separately. For this purpose, both eyepieces are equipped with graduated diopter scales to facilitate adjustment.
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