Nowadays, a person who wants to purchase high-quality modern binoculars has a lot of opportunities. The choice of a variety of equipment from world manufacturers is unusually large, including in online stores. But it’s best to choose the one that is right for you according to technical parameters and at the same time suits for the price.
This device is quite complicated in technical terms, and it is sometimes difficult for the average consumer to understand its characteristics. For example, what does “30x60 binoculars” mean? Let's try to find out.
What are binoculars
Getting to the choice, decide what approximation is enough for you to observe, will you use the device not only in bright light, but at dusk, will you be comfortable with a lightweight version, with which prolonged observation is possible? For the same 30x60 binoculars, reviews can be very different depending on the needs of the owner.
Therefore, it is so important to determine why you are buying this device and in what conditions you are going to use it.
Binoculars can be theatrical and military, marine or night vision, as well as small compact ones - for those present at the stadium during competitions. Or, conversely, large, designed for observation by astronomers. Each of the varieties has its own characteristics. Sometimes they differ quite significantly. To make a good choice, get acquainted with the main ones.
What is multiplicity?
This is one of the most important characteristics of such a device as binoculars. Multiplicity tells us about the ability to increase the environment. If, for example, its indicator is 8, then in the maximum approximation you will consider the observed object at a distance 8 times smaller than the one at which it is in reality.
Trying to buy a device with the highest possible multiplicity is unreasonable. This indicator should be related to the circumstances and place of use of the binoculars. For observations in the field, it is customary to use a technique with digits of multiplicity from 6 to 8. An increase in binoculars by 8-10 times is the limit at which you can carry out observation from your hands. If it is higher, jitter, amplified by optics, will interfere.
Binoculars with a significant increase (from 15-20 times) are used in conjunction with a tripod, which are mounted thanks to a special adapter or adapter. The large weight and dimensions are not conducive to long wear and in most cases are not needed, especially when the review is complicated by many obstacles.
Available models with variable multiplicity (pancratic). The degree of increase in them changes manually, like photo lenses. But due to the increased complexity of the device, they cost more.
What does "binoculars 30x60" mean, or let's talk about the diameter of the lens
The marking of any binoculars contains the size of the diameter of the front lens of its lens, which is given immediately after the multiplicity index. For example, what does “30x60 binoculars” mean? These numbers are deciphered in this way: 30x is the multiplicity index, 60 is the size of the diameter of the lens in mm.
The quality of the resulting image depends on the diameter of the lens. In addition, he determines the flow of light collected by the lens of the binoculars - it is the wider, the larger the diameter. Binoculars marked 6x30, 7x35 or, in extreme cases, 8x42 are considered universal for traveling conditions. If you plan to conduct outdoor observations in the daytime, and rather distant objects to be considered, take a device with an magnification of 8 or 10 times and a lens with a diameter of 30 to 50 mm. But at dusk they are not very effective due to less light entering the lenses.
The best binoculars for spectators at sporting events are small (pocket-sized option) with parameters of about 8x24; they are good for the general plan.
If there is not enough light
In poor lighting conditions (at dusk or at dawn), you should either prefer a device with a large diameter lens, or sacrifice multiplicity. The optimal ratio is 7x50 or 7x42.
A separate group - the so-called night binoculars - active and passive night vision devices. Passive lenses are equipped with a multilayer coating that eliminates glare. They are used in the presence of minimal lighting (for example, moonlight). Active devices also work in complete darkness, since they use infrared radiation. Their minus is the dependence on the power source.
Fans to study space objects (for example, consider the relief of the lunar surface) need binoculars powerful enough, with an increase of at least 20x. For a more detailed acquaintance with the night sky, an amateur astronomer is better to take a telescope, which in this case will not be replaced even by the best binoculars.
What is the viewing angle?
The viewing angle (or its field) is another important characteristic. This value in degrees indicates the width of the coverage. This parameter is inversely related to the increase - powerful binoculars have a small "angle of view".
Binoculars with a wide viewing angle are called wide-angle (or wide-field). They are convenient to take to the mountains to better navigate in space.
Often this indicator is expressed not by a graduated angle, but by the width of a segment or space that can be viewed at a standard range of 1000 m.
Other binocular specifications
The diameter of the exit pupil is the quotient of the division of the diameter of the entrance pupil by the magnitude of the multiplicity. That is, with 6x30 binoculars this indicator is 5. The optimal number in this case is about 7 mm (the size of the human pupil).
What does “30x60 binoculars” mean in this case? That the size of the exit pupil with this marking is 2. Such binoculars are suitable for not too long observation in good light, then the eyes are tired and overstressed. If the illumination leaves much to be desired, or long-term observation is ahead, this indicator should be at least 5, and preferably 7 or more.
Another parameter - the aperture “controls” the brightness of the image. It is in direct proportion to the diameter of the exit pupil. The abstract number characterizing it is equal to the square of its diameter. In low light, it is desirable to have this indicator of at least 25.
The next concept is focus. Being central, it is a universal means of quick sharpening. At the same time, its regulator is located near the hinge connecting the pipes. Those who wear glasses should preferably have binoculars with diopter adjustment.
What else is important
Other, not so global characteristics of binoculars, however, play a significant role in its selection. Depth of field refers to the size of the segment to the object of observation, on which it is not necessary to change the configured focus. It is the lower, the greater the multiplicity of the device.
Binoculars have the stereoscopicity (binocularity) characteristic of the human eye, which makes it possible to observe objects in volume and perspective. This is its advantage over the monocular or spyglass. But this quality, useful in the field, interferes in other cases. Therefore, for example, in theater binoculars it is minimized.
According to optical systems, binoculars are lens (theatrical, Galilean) and prism (or field). The former have a good aperture, a direct image, low magnification and a narrow field of view. Secondly, prisms are used that turn the inverted image received from the lens into a familiar one. Due to this, the length of the binoculars is reduced and the viewing angle is increased.
The transparency coefficient refers to the ability of the device to transmit light rays, expressed as a fraction. For example, with a loss of 40% of the light, this coefficient is 0.6. Its maximum value is one.
What is the case of binoculars
Its main advantage is durability. Shockproof qualities are ensured by the rubberized body, thanks to it, reliability is also achieved when held in hands and moisture resistance in wet weather.
Modern waterproof binoculars are so tight that they can be under water for a while at a depth of 5 meters without harming themselves. Lenses protect against fogging, filling the space between them with nitrogen. These qualities are important for tourists, hunters, naturalists. Binoculars with a rangefinder will be useful to the researcher, a device with a dull matte surface - to a lover of watching animals.
Certain non-standard functions of individual devices such as an image stabilizer, a laser range finder or an integrated compass significantly increase the cost of binoculars and are welcomed only when necessary. Decide for yourself - do you really need, for example, binoculars with a range finder, are you ready to overpay for this option.