Recommend me an astronomical telescope.

Refraction is suitable for beginners and easy to operate. The caliber used by beginners is generally 70-90mm, which is easy to carry and the time axis is not easy to change when moving. Although the price is slightly higher, the imaging quality is excellent. For novices, refractors with a diameter of 80~90mm are recommended within a budget of 2,000 yuan, such as TP2-80JDS of Sirius Ring-tailed Wolf II, 1.500 yuan; Star Trane 90EQ, price 1900 yuan; Or AstraZeneca 80EQ, with the German equatorial telescope, within 1000, the effect is not worse than Sirius. The money saved can be used to buy a 7×50 or 8×42 binoculars to cooperate with the sky survey.

Novices generally do not recommend mirrors. For beginners, reflection has an advantage that it is lighter and shorter than refraction with the same caliber, so it is convenient to carry. Moreover, the advantage of reflective telescope is that the image is clear and bright. For the same money, you can buy a telescope with a larger aperture than refractive telescope.

However, compared with refractive telescope, the optical axis of reflective telescope is easy to change. Because the lens barrel is not sealed, it is easy to produce airflow in the lens barrel, so it should be photographed outdoors 1 hour before observation to adapt to the outside air. It is difficult for beginners to adjust the optical axis of the mirror, and the mirror needs a thick film, which is not easy for beginners. The optical axis of the mirror is very unstable, the star image on the axis is very sharp, and there are serious aberrations off the axis. The primary mirror of high-end products such as Schmidt-Newton and Maksutov-Newton is spherical (non-parabolic), and the front end of the lens barrel adopts glass Schmidt correction mirror to correct spherical aberration.

The biggest advantages of reflection ratio refraction are color difference and price. Refraction will have color difference due to different refractive indexes, while reflection can be avoided. Refractors can be reduced by using advanced APO structure and ed glass, so as to achieve almost zero chromatic aberration, but only this group of lenses (calculated by 127mm) costs tens of thousands of yuan, while the mirrors with the same caliber only cost two or three thousand yuan.

In addition, add some personal opinions, the landlord had better confirm whether to buy binoculars, and it is best to consider these factors first:

Is the landlord's place suitable for observation?

Nowadays, one of the most important factors affecting astronomical observation is the light pollution in cities. In general, the sky in county towns can reach the brightness of 5 stars, and some have 4 stars. The sky brightness in big cities can reach 3, and the brightness in big cities or some areas with dense light sources can even reach 2 stars. What concept? In other words, you can only find about 20 stars in the sky at most. If there are bright light sources around (such as the overhead lights of some buildings), I'm afraid I can only see four or five celestial bodies such as the moon and Jupiter.

If the landlord lives in a county town with few lights, or lives far from the city center, you can refer to the following questions. If the sky is too bright, it's best not to buy a telescope, because the brightness of deep space objects that are generally visible is above 3, and what you can see is probably the Pleiades cluster in Taurus, which is not clear.

Does the landlord have enough time?

If the landlord does not have enough time, it will also affect astronomical observation, because the use of telescopes needs an adaptation period. If the landlord can use it for 2 hours every day, it will take half a month to get used to it (this is based on the landlord's certain astronomical knowledge and preliminary understanding of the starry sky). In fact, I just bought a telescope for half a month and basically only use it to see the moon, because the star finder is really not used to it, and the equatorial telescope is not easy to carry. If the landlord lives in a place where strong light hurts, he needs to be able to take time out to observe in the suburbs, pay attention to the time at night, and consider safety issues. If it is inconvenient, the telescope is likely to become a decoration.

Does the landlord have certain astronomical knowledge, especially the understanding of the starry sky?

If the landlord doesn't know the arrangement of constellations and the position of deep space objects, he may not see anything, because there is no way to start. Star map of the four seasons is an essential tool for astronomical observation. More than 20 basic constellations are best printed in your mind, and more than 20 constellations are best recognized. If the landlord doesn't plan to make an in-depth observation, there is no need to remember the remaining 40 constellations (in fact, I didn't remember them all).

Is the landlord's occupation astronomy or astronomy? Or just as a hobby or pastime?

If the landlord intends to engage in astronomy, he'd better start with astronomical books and don't rush to buy binoculars. In the meantime, you can buy a 7×50 binoculars to help you understand the starry sky. For astronomy books, you can subscribe to a set of astronomy enthusiast magazines first, and if you can, you'd better buy a bound volume of the last two years. There are also popular astronomy, basic astronomy or popular astronomy. In addition, I recommend constellations and Greek mythology and constellation world, which can help you recognize stars. You can also often go to Mufu Astronomical Forum to communicate with colleagues there. Just look at the telescope guide for astronomy enthusiasts in Cambridge.

Astronomy enthusiasts don't seem to have any standard equipment ... and then I said, it's just an 80600 telescope, two binoculars (a 7×50 and an 8×42), Fu ID, a Baidu ID (all with this name), a Stellarium (and a Skymap) software, a set of books, and that's all, like a star map or something.