What does the 30x60 binocular mean? How to determine the multiplicity of binoculars
In our time, who wants to buy high-quality modern binoculars a lot of opportunities. The choice of a variety of equipment from the world's manufacturers is unusually large, including in online stores. But it's best to choose the one that will suit you for technical parameters and at the same time arrange for the price.
This device is quite complicated in technical terms, and it is sometimes difficult for an average consumer to understand its characteristics. For example, what does "binoculars 30x60" mean? Let's try to find out.
What are binoculars
When choosing a product, decide what approach is sufficient for you to observe, whether you will use the device not only in bright light, but also in the twilight, will you be satisfied with a light version with which a long-term observation is possible? On the same binoculars 30x60 reviews can be very different depending on the needs of the owner.
Therefore, it is so important to decide what exactly you are buying this device for and in what conditions you are going to use it.
Binoculars can be theatrical and military, naval or night vision, and also small compact - for those present at the stadium during the competition. Or, on the contrary, large, intended for observations of astronomers. Each of the species has its own characteristics. Sometimes they differ quite significantly. To make a good choice, we will 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 exponent is 8, then in the maximum approximation, the observed object will be viewed at a distance 8 times smaller than the one on which it actually is.
Strive to buy the device with the maximum possible multiplicity is unreasonable. This indicator should be correlated with the circumstances and place of use of binoculars. For observations in the field, it is customary to use a technique with digits from 6 to 8. The magnification of the binoculars is 8-10 times the limit, at which observation can be made from hands. If it is higher, the jitter, reinforced by the same optics, will prevent it.
Binoculars with a significant increase (from 15-20 times) are used in the kit with a tripod, which is attached with a special adapter or adapter. Large weight and dimensions do not have a long bearing and in most cases are not needed, especially when the survey is hampered by a multitude of obstacles.
Models with variable multiplicity (pancratic) are issued. The degree of magnification in them varies manually, like photographic lenses. But in connection with the increased complexity of the device, they are more expensive.
What does "binoculars 30x60", or Talk about the diameter of the lens
Marking of any binoculars contains the size of the diameter of the front lens of its lens, which is given immediately after the multiplicity factor. For example, what does "binoculars 30x60" mean? These numbers are interpreted in this way: 30x - the index of multiplicity, 60 - 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 as a last resort 8x42 are considered universal for field conditions. If you plan to conduct observations during the day in nature, and consider rather remote objects, take the device with an increase of 8 or 10 times and an objective with a diameter of 30 to 50 mm. But in the twilight they are not too effective because of the smaller light entering the lens.
The best binoculars for spectators at sports events are small (pocket version) with parameters around 8x24, they are not bad for a general plan.
If light is not enough
In conditions of poor lighting (at dusk or at dawn) one should either prefer a large-diameter instrument of the lens, or give up a multiplicity. The optimal ratio is 7 × 50 or 7 × 42.
A separate group - the so-called night binoculars - active and passive night vision devices. Passive lenses are equipped with a multilayer coating, eliminating glare. They are used in the presence of minimal illumination (for example, moonlight). Active devices also work in complete darkness, since infrared radiation is used in them. Minus them - the dependence on the power source.
Lovers of studying cosmic objects (for example, consider the relief of the lunar surface) need binoculars quite powerful, 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 replace even 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 large viewing angle are called wide-angle (or wide-field). They are convenient to take in 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 distance of 1000 meters.
Other characteristics of binoculars
The diameter of the exit pupil is called the quotient from the division of the diameter of the entrance pupil by the magnitude of the multiplicity. That is, with binoculars with a marking of 6 × 30, this figure is 5. The optimal number in this case is about 7 mm (the size of the human pupil).
What does "binoculars 30x60" mean in this case? The fact that the size of the exit pupil at such marking is equal to 2. Such binoculars will suit for not too long supervision at good illumination, then to eyes there is a fatigue and an overstrain. If the illumination leaves much to be desired, or long-term observation is to be made, this indicator should be at least 5, and better 7 or more.
Another parameter - aperture "control" the brightness of the image. It - in direct proportion to the diameter of the exit pupil. The abstract number, which characterizes it, is equal to the square of its diameter. Under reduced illumination, it is desirable to have this index at least 25.
The next concept is focusing. Being central, it is a universal tool for quick focusing. Its regulator is located near the hinge connecting the pipes. Wearing glasses it is desirable to have binoculars with dioptric adjustment.
What else is important
Other, not so global characteristics of binoculars, nevertheless play a considerable role at its choice. Depth of field is the value of the segment to the subject of observation, on which you do not need to change the adjusted focus. It is the lower the greater the multiplicity of the device.
Binoclus is inherent in the human eye, the property of stereoscopy (binocularity), which makes it possible to observe objects in volume and perspective. This has the advantage over a monocular or telescope. But this quality, useful in the field, hinders in other cases. Therefore, for example, in theatrical binoculars it is kept to a minimum.
By optics systems, binoculars can be lenticular (theatrical, Galilean) and prismatic (or field). At the first - good aperture, a direct image, a small increase and a narrow field of view. Secondly, prisms are used that turn an inverted image, obtained from an objective, into a familiar one. This reduces the length of the binoculars and increases the viewing angle.
The coefficient of transparency refers to the ability of the device to transmit light rays, expressed in fractions. For example, with a loss of 40% of light, this factor is 0.6. Its maximum value is one.
What is the case of binoculars
Its main advantage is strength. Shockproof qualities are ensured by 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 stay under water for some time at a depth of up to 5 meters without harming themselves. Lenses protect from fogging, filling the space between them with nitrogen. These qualities are important for tourists, hunters, naturalists. Binoculars with a rangefinder will come in handy for the researcher, a device with a soft matte surface - an amateur watching animals.
Certain non-standard functions of individual devices like image stabilizer, laser range finder or built-in compass significantly increase the cost of binoculars and are welcome only when necessary. Decide for yourself - so you need, for example, binoculars with a rangefinder, are you willing to overpay for this option.