1. Specification: For example, 8×30 means that the power of the mirror is 8 times and the aperture of the objective lens is 30㎜.
2. About multiples: Many people always think that the higher the optical multiple, the better. In fact, the reasonable multiple of the telescope is related to the aperture and observation mode of the telescope, that is, the larger the aperture, the higher the multiple can be; Fixed observation with tripod can be higher than hand observation. If you buy hand-held binoculars, 7 ~ 10 times is enough, and it is best not to exceed 12 times. Otherwise, the higher the multiple, the smaller and darker the observation field of view, and the lower the observation effect, especially the jitter brought by the high multiple will greatly increase, making the observation scene unstable. The telescopes of military forces in the world, such as China, the United States and Russia, are mostly 6 ~ 10 times, because clear and stable imaging is the most important.
3. About the aperture: The larger the aperture, the greater the observation field of vision and brightness, which is conducive to observation in dim light. However, the larger the aperture, the larger the volume, which can generally be selected between 30 and 50 ㎜ as needed.
4. About the field of vision: The larger the field of vision, the wider, brighter and more comfortable the observation range. Conventional military telescopes generally adopt wide-angle and large-field design.
5. Coating: The purpose of lens coating is to reduce reflection, increase light transmittance and improve observation brightness. The color of the coating depends on the optical material and design. The thinner the coating, the smaller the reflection, the better. In recent years, all kinds of red and green film telescopes with strong reflection have appeared in various markets, which are very attractive to consumers. In fact, this inferior coating reflection will lose a lot of light, make the color colder and darker, and reduce the clarity. What's more, some people even call this inferior red film telescope an "infrared night vision telescope" that can be used for dark night vision to deceive consumers. In fact, the real infrared night vision device and low-light-level night vision device are all photoelectric cell imaging, which is completely different from the telescope.
6. What the telescope can see: This is mainly related to the performance of the telescope, the weather, the size of the target and the judgment criteria. According to the test, with the Russian-made 8×30 conventional binoculars, stones, human faces and moving vehicles can be clearly seen several kilometers away in clear weather, and many craters, moons of Jupiter, star clusters and nebulae on the moon can be seen at night. Friends who are interested in astronomy can try it. In fact, an excellent telescope will often bring you more fun and uses than you can imagine. Some businesses falsely advertise that 80 meters of an 8-fold telescope equals 8 meters. This statement is wrong and seriously ridiculous. Some businesses even advertise that they can see dozens of kilometers. I don't think many people can lift such a telescope.
7. Identification of regular Russian-made telescopes: In recent years, a large number of so-called Russian-made telescopes disguised as gray, black, white and green plastic shells have appeared in various markets, using only ordinary lenses and prisms. The lenses are painted with red film, green film, yellow film and other colors, and some are equipped with small compasses and coordinate lines, as well as Russian, Russian party emblem, cannon and Red Star. The so-called "Russian telescope" is marked dozens, hundreds or even thousands of times, claiming to be able to see dozens or hundreds of kilometers, but it is not an imitation of some domestic manufacturers. Its price is only one or two hundred yuan, and the quality is very poor. Its true multiple is only about 3 ~ 6 times. Real Russian military telescopes can only be seen in the border trade areas of Northeast China and Xinjiang, and few are delivered. Russian military telescope is characterized by all-metal structure, durability, serial number engraved on the mirror surface, high-quality composite achromatic optical lens, high-quality light blue, light purple and light yellow antireflection film, and BaK4-4 advanced prism material. The wide-angle design is true, and the high-definition optical quality is excellent, which fully embodies the superb optical level of the former Soviet Union and leaves a deep impression on everyone who has used it.
8. About the price: A famous telescope in the international market has good performance and exquisite packaging technology, but the general price is more than two or three thousand yuan. Relatively speaking, the same high-performance Russian conventional telescope, although the packaging and technology are not as good, but the price is much lower, which is very suitable for the choice of working class.
9. About military-grade telescopes: * * There are three kinds, one is the conventional military type, which is an all-weather telescope; Second, the troops that used to be equipped are now in poverty, such as all kinds of ranging telescopes with dense lines; Thirdly, on the basis of the military model, the dense bit lines are removed and changed into more convenient central focusing, which is supplied to the market, such as various conventional telescopes. Military-grade telescopes are superior to ordinary civilian telescopes in all aspects.
10, about domestic telescopes: At present, there is a flood of fake and shoddy telescopes in China, and many people have lost confidence in domestic telescopes. In fact, the level of China glasses industry is not low, and some high-quality products are mostly produced and exported by foreign manufacturers with excellent performance, but rarely seen in China.