For outdoor enthusiasts, it is a beautiful thing to have a satisfactory telescope. Due to the lack of knowledge about telescopes, many friends will buy at will or even be misled. So how should we buy outdoor telescopes? Woolen cloth?
An ideal telescope for outdoor sports
It should have the following characteristics:
It is nitrogen-filled and waterproof, and it is covered with rubber. It has suitable magnification and calibers, portability and ease of use. Of course, excellent optical quality is the minimum. The outdoor sports referred to here generally refer to hiking, backpacking and camping. The requirements for binoculars are much more complicated than ordinary tourism.
In order to prevent the infiltration of rainwater or the fogging of the lens in cold weather or even the entry of dust caused by long-term bad use, nitrogen-filled waterproofing can fundamentally solve this problem, even if it is thrown into the water, it does not matter, and some are not filled with nitrogen The airtightness of the military telescope is actually very good. As long as it is not soaked in water, the general rain, snow and sand can still be dealt with.
Long-term use in the field, unintentional bumps and bumps are unavoidable, and telescopes with unsatisfactory design structure or work materials can easily lead to optical damage such as axial deviation ghosting. Therefore, a thick layer of rubber is wrapped around the mirror body. Very good protection that improves feel and grip in addition to shock absorption. Outdoors, the purpose of the telescope is to observe the terrain, enjoy the scenery, and watch birds and animals. Considering the hand tremor and optical requirements, it is very suitable to use a magnification of 6-8 times.
As for the caliber, 20-40mm is ideal depending on the emphasis and requirements of use. Outdoor sports itself requires individuals to carry a large amount of equipment and supplies. In the case that every gram of weight affects physical strength, it is unrealistic to one-sidedly pursue optical performance and ignore volume and weight. In a sense, it can be said that weight The contradiction with optical performance is irreconcilable. Large-diameter and high-brightness mirrors will inevitably lead to a sharp increase in the overall weight. Therefore, you can only make a satisfactory compromise between weight and optical requirements according to personal requirements and preferences. The roof prism telescope has a relatively small volume and weight, and is easy to carry. The disadvantage is that the price is relatively high due to the complicated manufacturing.
Some basic optical indicators about telescopes have their own separate definitions for outdoor sports, resolution: This is the primary indicator, and a mirror with poor resolution can help you see a crocodile as a tree trunk. Exit pupil: It can be simply calculated by dividing the aperture by the magnification. The larger the number, the more suitable it is to capture your prey in low light.
Color reproduction: Color casts exist in many telescopes, and general observation may not be so strict, but if it is used to look at birds in the wild, you cannot correctly describe the color of bird feathers. Coatings: Fake Russian binoculars with street-bright red coatings are a real rape to the eyes, they cause a sharp loss of light, color reproduction problems, and unpleasant glare, and the best coatings can make the lenses almost invisible .