Ask about astronomical telescopes.

Beijing Galaxy Telescope Answer:

The gap between astronomical telescopes is very large, and our ordinary junior astronomy enthusiasts can choose non-professional mirrors (professional mirrors are very expensive, and they are generally used for professional observation). **In the 1000-2000 yuan or so low-end astronomical telescope can be, of course, if you are very passionate about astronomy, for the observation effect of high requirements, you must choose the high-end telescope, refraction and reflection have their own advantages and disadvantages, mainly depending on what you want to observe, choose the best one for yourself;

The refractive aperture is relatively small, the focal length is relatively long, and the realization multiple is relatively high, which is more suitable for seeing the single planet and details, but it is easy to maintain, simple to operate, and the low-end refractor is relatively cheap, which is more suitable for beginners.

The reflective type has a large aperture, a short focal length, and a relatively low realization multiple, which is more suitable for seeing a large area of starry sky and a large observation field, but it needs to be coated once every five years or so.

The realization multiples mentioned above are relatively speaking, the magnification of astronomical telescopes is directly related to the eyepieces, and the eyepieces that are standard with each model are different and cannot be generalized. For beginner astronomy enthusiasts, it is still recommended to choose the refractive type.

For entry-level astronomical telescopes, the Centron 90EQ (refractive type) and 130EQ (reflective type) are both good choices.

90EQ This can see the crater on the surface of the moon, can see Saturn, Jupiter, Jupiter moons, etc., can also view, can see the trademark of one or two kilometers of air conditioning, this basic configuration is very good, the imaging effect is also great, ** at about 1590 yuan.

130EQ can see the craters on the surface of the moon, Saturn's rings, Jupiter, Jupiter's cloud belts, Jupiter's moons, etc., and 130EQ is basically a civilian astronomical telescope that can shoot nebulae with the lowest aperture requirements after being connected to the camera. **Around 1550 RMB. The relative aperture of 130EQ is large, and the observation field is large.

You can go to the Galaxy Telescope Knowledge Area to see, you can directly search for "Galaxy Telescope", where there is a lot of relevant knowledge about the purchase, maintenance and use of telescopes

If you buy an astronomical mirror for photography, don't pay too much attention to the size of the aperture, a small aperture refractor can shoot high-quality **, the first choice is a refractor such as ED or APO, because this kind of mirror has no obvious chromatic aberration in the case of high magnification, and you can get high-quality **! According to your budget of 3000 yuan, you can buy an ED astronomical mirror with an aperture of 80mm, but if you want to take pictures, you also need a high-quality automatic tracking equatorial mount for a long time**! Therefore, a budget of 3,000 yuan is a bit difficult for astrophotography!

The study of astronomical telescopes requires basic knowledge: there are three types of astronomical telescopes: refracting astronomical telescopes, reflective astronomical telescopes, and catadioptric astronomical telescopes.

1. The refracting astronomical telescope is more convenient to use, with a larger field of view and bright star images, but there is chromatic aberration, which reduces the resolution. The objective lens of a high-quality refractor is either a two-element double-split achromatic objective or a three-element apochromatic objective. However, achromatic or apochromatic does not completely eliminate chromatic aberration.

2. The advantage of the mirror astronomical telescope is that there is no chromatic aberration, but the coma and astigmatism of the mirror are large, which makes the image quality at the edge of the field of view worse. There are two types of mirrors commonly used: Newtonian and Cassegrain. The former has a simple optical system, with a spherical mirror at the rear end and an eyepiece on the front side; The main and secondary mirrors of the latter optical system are aspherical, and the primary mirror and eyepiece are in the back, and the imaging quality is better and more expensive.

3. The catadioptric astronomical telescope takes into account the advantages of the refractor astronomical telescope and the reflector astronomical telescope: large field of view, good image quality, short lens barrel and easy to carry. Compared to refracting telescopes with equal focal length and the same aperture, ** is less than a third.

Advantages of astronomical telescopes:

Large field of view, good image quality, short lens barrel, easy to carry. Compared to refracting telescopes with equal focal length and the same aperture, ** is less than a third. There are two types of catadioptric mirrors: Schmidt-Cassegrain and Maksutov-Cassegrain, the latter is also known as the Ma-Cage mirror.

There are two types of horse card mirrors: two-piece and three-piece. For example: Boguan.

Because the image quality is better than that of the two-piece type, it is very popular with astronomy enthusiasts at home and abroad. 2. Reasonable selection of the focal length of the astronomical telescopeThe focal length of the astronomical telescope is related to the celestial body you want to observe. If you want to observe nebulae and look for comets, choose a short-focal length astronomical telescope; If you want to observe the moon and planets, choose a telephoto astronomical telescope; If you want to see binary stars, concentrating stars, variable stars, and star clusters

It is better to choose a medium focal length astronomical telescope. Medium focal length lenses can be used at both ends, so they are more popular. Generally, a short lens means that the ratio of focal length to aperture is less than or equal to 6, and a long lens means that the ratio of focal length to aperture is greater than 15, and it is called a medium focal length lens in between.

3. The magnification of astronomical telescopes is not always larger, according to the experience of astronomers over a long period of time.

1. Do not use the telescope directly **sun,**the sun must pass the projection method or have special filtering measures;

2 Don't treat telescopes as toys, telescopes are precision optical instruments that should be used and maintained carefully.

3 Don't think that you can see everything with a telescope, you can indeed see the details of celestial bodies and celestial bodies that cannot be distinguished by the naked eye through a telescope, but the better the effect, the higher the one, there is no perfect telescope, the most important thing is to choose the one that suits you;

4 For every telescope, there is a suitable magnification. Exceeding this multiple does not enhance the ability to distinguish, but rather makes the object very dark and difficult to see. 60 80 caliber telescope, the appropriate magnification should be less than 100 times, 200 times magnification can not see anything.

5 If you can't identify more than five constellations in the night sky, don't rush to use a telescope, because you can't find observable stars, you can only look at the moon;

6 Astronomical telescopes can also often be used for landscapes or flora and fauna, and can easily obtain higher magnifications than binoculars. However, the magnification should be less than 100 times, and 20-50 times is the most appropriate.

Astronomical telescopes are divided into two categories: refracting telescopes and reflecting telescopes. They have their own characteristics and should be used flexibly. The usage and steps are as follows:

Adjust the optical axis of the guide mirror (the attachment that determines the field of view of the target in order to capture the target object) and the optical axis of the telescope so that they are parallel. (Due to the high magnification of the telescope and the narrow field of view, in order to capture the target object, it is necessary to have a guide mirror with a wide field of view.) Find a long view during the day, first adjust the optical axis of the guide and the telescope to parallel).

Adjust the bracket platform to keep the water leaking, Sun Ping's answer to the stool (adjust the length of the three legs).Adjust the polar axis of the telescope so that it points to the celestial north pole (only with an equatorial mount, this is done when shooting** or long-term tracking).Attach the eyepiece.

Magnification = objective focal length eyepiece focal length. The magnification should be within 10 times of the diameter (cm). Peek into the guide so that the star being observed is at the intersection of the reticles.

Adjust the tube to focus (it is advisable to adjust the tube to see a clear image of the star.) If the optical axis is corrected when it is like skewed).