Nowadays, there are many red film binoculars with strong mirror reflection and shining light on the market. Some dealers call them “infrared”, “sub-infrared”, “ruby coating” and so on. They will also tell you that they are capable of “Infrared Night Vision Telescope” for observation at night. Please friends don’t be fooled! The real infrared night vision device is to receive infrared invisible to the human eye. It uses photoelectric tube for imaging. It can only be observed with a battery. It cannot be used during the day. It is completely different from the structure of the telescope. The price is also very expensive. The price of the low-light tube must be at least several thousand to tens of thousands of yuan or even higher (military-grade)! If you can buy an “infrared night vision telescope” for tens or hundreds of yuan, isn’t it a dream? In fact, the bright red film greatly reduces the brightness of the image due to the serious reflection of light. Only when the sun shines on the snow and makes the scene dazzling, it can play a role in reducing the brightness.
If you wear glasses, how should you choose binoculars?
As your eyes get closer to the eyepiece, when you happen to be able to see the entire field of view or the target in the field of view clearly, the distance between your eyes and the eyepiece is called the “exit pupil distance”. The exit pupil distance of different telescopes is different, generally between 5 and 20mm. The rubber eyecup above the eyepiece is set up to make the eyes at a suitable distance and feel comfortable during observation. If you need to wear your eyes to watch the binoculars, then the distance between the eyes and the eyepiece will become larger, so choose a larger exit pupil distance.
Which type of binoculars is suitable for starry sky observation?
If you use binoculars to observe the starry sky, the aperture of the objective lens is the most critical, because it directly determines the resolving power of the telescope. If you want to hold the binoculars in hand, the aperture should be 50 or 60mm, and the magnification should be 7~8 times; if you plan to use the binoculars on a tripod, the aperture can be increased to 70~80mm, magnification It can be increased to 20 times.
Of course, if you want to get a better starry sky observation effect, then it is best to buy an astronomical telescope.
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