Binoculars are optical instruments.
Binocular refers to that which demands the attention of both eyes at the same time . When analyzing the term, one discovers that it is a compound word that results from the union of two Latin words: binus (translated into Spanish as “double” ) and ocularis (interpreted as “ocular” ).
The term is intended to identify the optical element that allows you to look or observe simultaneously with both eyes . Binoculars are also known as binoculars or binoculars and their function is to increase the image of objects not so close that can be seen through the device.
Binoculars and other optical instruments
The telescope and monocular are other optical instruments that enlarge images. The main difference with binoculars is that they generate the effect of stereoscopy (that is, they recreate the illusion of depth of the image). Stereoscopy is achieved thanks to the fact that each of the two tubes of the binocular contains various lenses and a prism , which allows the image to be magnified for each eye in particular.
The light passes through the series of lenses until it reaches the prisms, which are responsible for placing the image in its correct position through the principle of total internal reflection. This also differentiates binoculars from telescopes, which display the image inverted.
Binoculars can be used for bird watching.
Different types
It should be noted that there are multiple models and types of binoculars. Most of them offer the possibility for the user to adjust the separation between the eyepieces for greater comfort. Binoculars also typically feature a dioptric correction ring (installed on the right eyepiece to improve focus) and include focusing wheels .
The magnification level of the images and the diameter of the objective is measured in millimeters and is expressed with a pair of digits that are separated by an X. The 14x60 binoculars, for example, offer a 14x magnification level and a pair of 60 millimeter diameter objectives.
Tips for choosing the ideal binoculars
To know what magnification a binocular has, just pay attention to the first figure that appears in its measurement; If you have a 10x50 device, it means you can enlarge or reduce the size of the object up to 10 times. That is to say that if we are going to observe the Moon with it, which is at a distance of 384,000 km, we will see it as if we were at a distance of 38,400 km.
Regarding the field of view , this data indicates the angular size allowed by the device. If you have a field of view of 7º, you can observe objects that may be within a diameter of 7º. It is worth mentioning that some models refer to the visual field in feet or meters; that is, in a straight line. Both values are important and that is why it is good to know how much of one a value of the other is equivalent to. For example, if the binocular has a field of view of 373 feet, its equivalent in degrees is 7.1º. It is calculated through the following formula: C (visual field in degrees) [º] = Arctg (L (linear visual field) / 914m (linear field constant).
Other fundamental aspects to take into account when choosing the ideal binoculars are:
- The aperture : indicates the amount of light that enters; The larger this is, the more detail can be achieved in visibility.
- Magnification : indicates the level of zooming in or out that can be achieved; The larger this value, the smaller the field of visibility . This detail must be considered taking into account the opening; It is necessary to find a balance between both values.
- Exit pupil : refers to the diameter of the light beam emitted by each eyepiece and is measured in millimeters. It is extremely important to take it into account, especially for binoculars that are going to be used for night observation .
- Eye and focus adjustments : those devices that are more malleable and that allow you to customize the focus and the observing eye, are the most recommended, due to their versatile quality; However, it is always advisable to be clear about the use that the binocular will give to know which device to choose.