Some binoculars attract customers with a variety of additional features. This should be an objective analysis.
Shan Some Soviet military dual-cylinder mirrors have infrared night vision function. It looks tempting, but it doesn't help the stars. Because it can only dimly see the dark body, the engine and other infrared sources, the image is not clear, the infrared light emitted by celestial bodies is much weaker than this, and is basically absorbed by the atmosphere.
The Shan zoom feature is one of the features of imported high-end binoculars, which can change magnification in the observation and make the price more than 10 times times higher than the other two-cylinder mirrors of the same caliber. The minimum magnification of Gio is 7x or 8x, and the highest is about 25x. At high magnification, it can only barely discern Jupiter's surface, Saturn's ring or Venus phase, but it certainly cannot see the polar crest of Mars. These astronomical phenomena are more clearly seen in a self-made one-cylinder mirror (about 6 centimeters in diameter) that costs almost hundreds of dollars. On the other hand, the complex zoom system will certainly increase the aberrations, making the image quality of the binocular mirror less than the fixed magnification.
Shan navigation, military binoculars in the eyepiece system often has a scale or checkerboard, it is to measure the angular diameter of celestial bodies, moving speed is helpful.
Shan Rubber Goggles help to watch the stars, block the stray light from the surrounding area and keep them from interfering with the eyes.
Attachments such as the Shan Compass may be useful for travel, but they are not used when viewing stars, only to increase the price. But the objective lens and eyepiece cover (cover) absolutely need, can moistureproof dustproof. Even if the bought binoculars do not have a lens cover (hood), they should be made into a homemade pair.
Use and Maintenance
The binocular is small and compact, and sees a positive image, plus a wide viewing field, which is much easier to use than a small telescope. However, binoculars also have shortcomings, such as small diameter, low magnification, not suitable for photographic observation. Only by the advantages and disadvantages can the maximum benefit be exerted.