How to choose a telescope

1, you need to know your purpose in advance:

Whether watching performance competitions, hiking outdoors, watching birds and stars, or watching the scenery on the balcony, telescopes with different volumes and weight multiples are needed for different purposes.

2, need to clearly inform the psychological price:

For the same specifications, the price can range from tens of yuan to thousands or even tens of thousands of yuan. For products with similar prices, the quality gap may be relatively large. Only when the price is clear can we make the best recommendation.

3. Believe the recommendation of old players:

The experience of old players cost a lot of money and time. If you don't want to pay tuition, then old players must listen. After all, they just sit in front of the computer and daydream. Players really play for a long time, and many products.

4. Don't choose products that are too obscure and nobody cares:

A novice has almost no chance to screen out the fine products that countless players have not found with his unique eyes among a dime a dozen products.

5, don't use desire instead of thinking:

To be powerful, to be dual-powered, to be pocket-sized, to look at XX 10 kilometers away, and so on, desires must obey the reality-the basic physical laws and how high the price can be, and fantasy is meaningless.

6, don't use intuition instead of thinking:

For example, high magnification is better than low magnification, variable magnification is better than fixed magnification, military is better than civilian, imported brands are better than domestic brands, big brands are better than small brands, and big brands are better than niche brands. Don't jump to conclusions easily, read more books, ask more questions and think more.

7. resist temptation:

Many low-end Amoy brand telescopes boast about their product introductions. There is nothing in the sky and nothing on the ground, so I thought: why is it so good and so cheap? The ancients said that it is not wrong to buy the essence that is never sold. The economic law of "one price, one goods" will not fail.

8, learn to compromise:

Make a reasonable choice among factors such as price, volume, weight, multiple, caliber and brand. Don't expect everything to be what you want. Only a liar will tell you that his product meets all your requirements.

Extended data:

Common parameters of telescope

1, magnification

What is the ratio of eyepiece angle to objective angle? [2]? The magnification of a telescope is usually calculated by the ratio of the focal length of the objective lens to the focal length of the eyepiece, indicating the magnification of the telescope's viewing angle. For example, a telescope with a magnification of 10 means that an object with a viewing angle of 1 degree can be magnified to 10 degree.

2. Perspective

(field of view) indicates the visible scene range of the product at 1000m, such as 126m/ 1000m, which means that the telescope can observe the field of view at 1000m away from the observer.

3. Pupil diameter

Is a parameter that roughly describes the imaging brightness. In low light environment, the larger the diameter of the exit pupil, the clearer the image will be. People's pupil, under normal physiological conditions, will not exceed 7mm at most, so the exit pupil diameter greater than 7mm is a waste of light unintentionally.

Step 4 solve

Resolution is the accuracy of the screen image, which refers to the number of pixels that the display can display. Because the points, lines and surfaces on the screen are all composed of pixels, the more pixels a display can display, the finer the picture will be, and the more information can be displayed on the same screen area, so resolution is one of the very important performance indicators.

5, dusk coefficient

Published by Zeiss Optical Company in Germany. It reflects the observation efficiency of telescopes with different calibers and magnifications in dark light. Calculation method: the product of telescope magnification and aperture is square.

6. Effective caliber and relative caliber

The distance from the center of the objective lens to the focus is called the focal length of the objective lens, which is denoted by the symbol F. The part of the objective lens diameter that is not blocked by the lens frame and diaphragm is called the effective aperture of the objective lens, which is denoted by the symbol D. The performance of astronomical telescope is mainly marked by these two data.

7. Light-gathering ability

In the dark, the pupil diameter of the human eye is generally around 7 mm, so the multiple of the effective area of the telescope objective relative to the pupil area is called light collecting ability. That is: light collection capacity =(D*D)/(7*7), where d is in millimeters.

Baidu encyclopedia-telescope