How to tell whether a telescope is good or bad, true or false?

Methods to identify the quality of telescope;

1. brand: At present, the binoculars on the market are mixed, so it is best to choose a regular big manufacturer with good reputation and guaranteed quality and after-sales. But as for domestic or imported goods, it depends on the money in your pocket. If you have no worries about money, of course you will sell Zeiss and Lycra. If not, it is recommended to make it in China, which is quite cost-effective (5- 10 times different from imported mirrors, but the actual picture quality is not so bad). China's technology of making optical glass is quite famous in the world.

2. Coating: You can often see that the objective lens of the telescope is red, green and green on the booth. It's not necessarily a red (green) film, but a decorative film, with colored plastic films on the glass. It is conceivable that the function of coating is to correct chromatic aberration and increase the amount of light entering. If you attach this plastic film again, it will inevitably block the light. I lied to you that it was a night vision telescope. I was completely fooled! In addition, the broad-band antireflection green film is more suitable for coating and the reduction color is better. Red film is used in relative environment (such as snow), and things look blue.

3. Multiplicity and aperture: the magnification of hand-held observation should not be too large 7- 10 times, and not more than 12 times at most. If it is too big, it will shake and you can't see clearly. Don't blindly pursue large magnification. The binoculars 50 times or 100 times on the market are basically lying to you, and there is no discussion! Of course, the larger the aperture of the objective lens, the brighter the image, but holding the aperture of 40-50MM for 7- 10 times is almost enough.

When a telescope observes a scene, the higher the brightness, the better. The multiple and aperture should preferably match 7x50 (7 times the aperture of a 50 mm objective).

4. Prism: BAK4 prism is the best choice.

It's best to be practical and compare the actual image quality to understand the quality of the mirror.