How to buy the best bird-watching telescope?
When feeding the belly was no longer a problem, people in pursuit of elegance found more pleasure in watching birds dance beautifully than in cooking and eating them, and bird-watching became fashionable. Instead of shotguns, people began to come to the woods, swamps, and beaches with goggles, big and small, to watch and photograph birds without disturbing them. Learn how to buy the best bird-watching telescope.
1. Get to know the bird-watching telescope
The bird-watching telescope is a kind of specialized bird-watching and set up, in the telescope bird-watching telescope occupies an important application field, in view of the domestic bird-watching enthusiasts gradually increase, so there are common bird-watching telescope and astronomical bird-watching telescope. A bird-watching telescope is a useful tool for ground observation, especially for bird-watching.
2. How to buy the best bird-watching telescope?
(1) Optical type
There are many types of monoculars available on the market, but not many are suitable for bird-watching. First of all to exclude is “reflective telescope”, such as Newtonian, the person must be in the side of the mirror tube observation, and into the image of the inverted image. The Trans is also not very good for bird-watching because of its extremely long focal length and high magnification.
And the primary mirror and secondary mirror are plated with silver, which will lead to light loss and yellow color. In addition, the secondary mirrors can also cause the diffraction of the incident light, leading to the reduction of clarity. Therefore, generally speaking, “bird-watching single barrel” is basically refraction type, the diameter is too large, the focal length is the too-long single barrel is not suitable for watching birds.
Therefore, at present, we can see the mainstream bird-watching single-barrel mirror is less than 100 mm diameter “short focal refractor”.
The larger the aperture of the objective lens, the better its ability to collect light. The eye responds to the energy of light, and the energy entering the eye directly affects our ability to perceive detail. Especially in the case of strong contrast between light and dark, morning and evening, cloudy, the larger the aperture, the higher the amount of light, the eyes can see more details. But at the same time, the heavier the telescope, looking at it for a long time is more likely to cause fatigue. It is advisable to choose a larger caliber according to personal physical ability.
Bird-watching activities are often carried out outdoors, observing the changing environment, it is best to choose nitrogen-based waterproof and fog-proof binoculars, so as to make the mirror in bad weather without fog and mildew, and the surface coated binoculars, not only shockproof effect is good, hold up is also more comfortable.
Visual field refers to the range of vision from 1000 meters, the width of the visual field should be higher than 104 meters, that is, 6 degrees. The bigger the field, the faster the search. However, the larger the field of vision, the more serious the distortion and blur of the edge, the more complicated and difficult the correction of aberration, the higher the technology and cost.
Bird-watching telescope generally chooses 8 times and do not exceed 12 times, more than 12 times need to stand to watch, otherwise useless because it will shake badly, affect the effect of bird-watching.
3. Three advantages of bird-watching goggles
First: bird goggles can zoom, that is if the bird’s distance from the observer changes.
Second: you can focus to prevent the wrong focusing, bird-watching mirror has a relatively large field of view, which is very good for observation and looking for birds.
Third: bird-watching mirror changes field of view more convenient, fast, do not have to worry about birds moving quickly and can not find.
For a bird-watcher, the performance of a telescope in the field can be summed up in three categories: image quality, ease of use/handle, and water resistance. The perfect bird-watching telescope should show the exact details and colors of birds, just as we see them in front of us, at all distances, and in all light conditions. You can carry them around all day without feeling mentally or physically tired. In the rain or accidental flooding, in violent temperature changes, in all possible collisions and vibrations should be safe.