Help me explain the parametric significance of astronomical telescopes

1. Choose according to the type: refractive astronomical telescope, reflective astronomical telescope, catadioptric astronomical telescope.

2. Choose an astronomical telescope with a large aperture according to the budget: it can maximize the effective magnification, the effect is good, the received light energy will increase step by step, and the farther and darker celestial objects can be observed, and the resolution is high, and more details can be observed.

3. Choose the right telescope focal length: It is recommended to choose a short focal length astronomical telescope for observing nebula comets, a medium focal length astronomical telescope for observing double star clusters, variable stars and star clusters, and a long focal length astronomical telescope for observing the moon and planets.

Astronomical telescopes:

Astronomical telescopes are the main tools for observing celestial bodies and capturing information about celestial bodies. Since Galileo Galilei built the first telescope in 1609, telescopes have continued to develop, from optical bands to full bands, from the ground to space, telescopes have become more and more observant and can capture more and more celestial information. Humans are expected to have telescopes in the electromagnetic band, neutrinos, gravitational waves, cosmic rays, etc.

Space is a good place for astronomical observations. Due to the absence of shielding and interference from the Earth's atmosphere, many types of astronomical telescopes are located in space. Most of these observers are well-designed and fully functional, some of which function as both telescopes and detectors.

There are many parameters, all of which are only approximate, and the specific can be subdivided, and you can add questions if you are interested. The first important parameter: aperture largely determines the resolution and ultimate magnitude.

The entry is at least 80mm, and below this is included in the ranks of toys. The second most important parameter: focal ratio The focal ratio and lens type affect the brightness of the field of view, but also affect chromatic aberration and coma.

There is also the focal length, which determines the magnification of direct focus photography. (The magnification is equal to the focal length of the objective lens divided by the focal length of the eyepiece, this does not need to ask the merchant) Additional important parameters: optical path type:

Refraction, Reflective or Refractive Lens Type: For Refraction: Pop-up, Fluorite, ED-APO Coating Type:

For refraction: single-layer coating, full-coating bracket type: equatorial mount, theodolite, photographic bracket (there are many types of equatorial mount and theodolite, I can't speak clearly, study it slowly.)

Ignore the camera stand) Focus type: gear focus, toothless focus, dual-speed focus. (Good focus is very helpful for photography, it doesn't matter if you look at it anymore) Eyepiece type:

The most common are K (lower range toy match), PL (normal telescope match), OR (lower gear binoculars match). This is according to the optical path system. In addition, eyepieces are also available in fluorite and normal, with different focal lengths.

Interface size: focusing seat and eyepiece inch (pure toy), inch (ordinary), 2 inch (higher-end) brand type: brand is also very important, what can be bought in China is:

Takahashi; Virtue; Jinghua, Sky Wolf, Boguan; Xingtron, East Star; Phoenix; Jiehe et al. I won't introduce them one by one, so let's check them out for myself. Note:

Look at the lenses to see if there are any mold spots and whether the coating is damaged. Look at the manual again to see if the accessories are consistent with the accessories in the manual. Finally, look at the optical quality of the mirror, including resolution, contrast, etc.

The quality of a telescope is not only related to the objective, but also to the eyepiece, prism, barrow, and all the accessories involved in the optical path. Improving the quality of accessories can help improve the overall quality of the telescope. Note the Supplementary Provisions:

Don't buy it in the mall, you won't pay for it. Don't ask questions such as "how many times" and "how far can you see" as soon as you come up, merchants like to smash laymen's hammers, and it's not a bad thing to pretend to understand when you buy something, but you should also have some understanding before.

Look at the caliber.

However, the larger the caliber, the more expensive it will be.