Generally speaking, telescopes can be divided into binoculars, monoculars and astronomical telescopes. We usually refer to the binoculars as binoculars. The price of binoculars ranges from tens to tens of thousands of yuan, and the gap is so large. How to choose? The following will teach you to choose binoculars from a relatively easy-to-understand aspect, and will also list some of the best reputation on the market. The binoculars for your reference.

How to buy binoculars, detailed explanation of parameters, to answer what kind of binoculars are good for you

We often hear friends who come to buy telescopes and ask: "How far can your telescope see?", "How many times can your telescope magnify?", "How much can your telescope magnify the stars in the sky?"... Issues such as these reflect the public's lack of knowledge about telescopes and astronomy.

The so-called "how far to see" and "how much to zoom in" are neither scientific nor meaningful, and the quality of telescopes is by no means evaluated in this way.

In fact, "how far to see" depends entirely on the brightness of the observed target. As long as the target is bright enough, you can see infinity without a telescope. For example, about 6,000 stars that we can see with the naked eye can actually be considered as At infinity; and "how big" is a question that is raised due to lack of basic knowledge of astronomy, this is because more than 99.9% of the "stars in the sky" we see are stars, and the stars are so far away from us, so Even if they are observed with the largest telescope on earth, they are still just geometric bright spots (the smaller the bright spot, the higher the optical imaging quality of the telescope; on the contrary, if you see the stars in the telescope have a surface or even a color, then It can be concluded that its optical system has serious drawbacks), only those celestial bodies in the solar system (such as the sun, planets, satellites, comets, etc.) or celestial bodies outside the solar system (such as nebulae, galaxies, star clusters, etc.) can be magnified with the help of telescopes.

So is "magnification" the first performance index to consider when purchasing a telescope? Absolutely not! Not only does it not rank first, but if it is selected too large, it will seriously deteriorate the imaging quality.

Magnification (should be between 8 times and 10 times)

The telescopes are marked with the words 10 x 42, 8 x 30, etc. The former represents the magnification and the latter represents the diameter of the objective lens. Using a 10x telescope to see a bird standing at 100 meters is as close as it is to the naked eye at 10 meters. Because the magnification is too large, the viewing angle is smaller, it is more difficult to search for the target, and it is easier to affect the clarity due to trembling of the hands. When the light is very sufficient, 10 times is clearer than 8 times; when the light is insufficient, 8 times can see details better than 10 times, so high magnification should not be blindly pursued.

Diameter (preferably between 30mm to 42mm)

The larger the aperture, the better. The diameter of the objective lens affects the amount of light entering. Especially in the case of strong contrast between light and dark, morning and evening, and cloudy, the larger the aperture, the higher the amount of light entering, and the eyes can see more details; but at the same time, the heavier the telescope, the more likely to cause fatigue when watching for a long time. It is advisable to choose a larger diameter according to individual physical fitness.

Field of View (the bigger the better)

The field of view refers to the range that can be seen from 1000 meters, and the width of the field of view should be higher than 104 meters or 6 degrees. The larger the field of view, the faster and easier it is to find the target. However, the larger the field of view, the more serious the distortion and blurring of the edges, the more complicated and difficult the correction of aberrations, and the higher the required technology and cost.

Color Fidelity (the more natural the better)

High-quality telescopes must faithfully reflect the primary colors and color saturation of the scene. In order to increase the brightness of the telescope, some manufacturers deliberately increase or decrease a certain light wave, which leads to distortion and makes the scene appear bluish or reddish.

The relationship between light transmittance and coating is inseparable and directly affects color fidelity. All optical glass has high light transmittance and multi-layer coating on the whole surface, with high brightness and accurate color reproduction. Generally, manufacturers will not publish all the data (it is difficult to do so), and some manufacturers will publish the light transmittance or coating of local optical glass to mislead consumers.

Use performance

depth of field

For bird watchers, the depth of field is a relatively contradictory parameter. If the depth of field is large, there is no need to adjust the focus frequently, which is more convenient to use. However, for the observation of forest birds, the foreground and background are not easily blurred, and the birds are not easy protrude. And the depth of field is small, although the foreground and background blurred obviously when observing the forest birds, and the bird theme is prominent, but when the distance changes, it is necessary to refocus, and the fingers must always be on the focusing wheel, which is more tiring. It depends on personal preference, there is no set standard.

tightness

Telescopes are often carried out outdoors, and the observation environment is changeable. It is best to choose a telescope that can prevent water immersion (water pressure and waterproof), so that the interior of the mirror can be kept sealed and stable, without fog and mildew.

comfort

Comfort varies from person to person. Generally speaking, for the surface-coated telescope, not only the anti-shock effect is good, but also more comfortable to hold; the weight of the mirror body determines whether it is convenient to use and carry for a long time; usually, everyone will choose a telescope with high durability.