Many people have such questions. Why do telescopes provide bird watching, astronomy, photography and other functions? Classified according to the optical system, the telescope can be roughly divided into three types: refraction, reflection, and catadioptric. According to the characteristics of various optical systems, it is more suitable for the purpose of birdwatching, astronomy, photography, and so on. Bird telescopes can also be used for astronomy, and of course telescopes can also be birdwatching.
Refractor telescopes are more expensive, they are cheaper to reflect, they are cheaper to reflect, and they can buy more than twice the diameter of refractors. For astronomical observing telescopes that are "big in a big deal," observations are better. Dark clouds and galaxies are certainly the most suitable. But for high-magnification planets, lunar surface observations, or astrophotography, I personally prefer APO-grade refractometers over 10cm in diameter, preferably APO-grade refractors (of course, very expensive) over 15cm in diameter so if your use is in astronomy On the other hand, the budget is more lenient and it is best to have one refraction. For bird-watching, because it is used during the day, it does not require strong light collection. What is needed is a sharper image, lighter portability, and it is better to attach the camera function. Therefore, bird-watching is most suitable for caliber 8CM focal length. Refractor telescopes below 500mm and objective lenses above the SEMI-APO level can minimize the problem of chromatic aberration in refractors. .
Most commercial built-in bird mirrors have built-in positive prisms. When shooting, prisms will produce unnecessary and unnecessary color aberrations. If you like photography, it is best to choose external positive-fit prisms. If you want to buy reflective telescopes, do not buy below 15cm, because you lose the advantages of cheap and large mirrors. The reflectors are mostly used in astronomy. It is not necessary to watch birds. It's just a bit weird. There are also a few of them. Friends use a 10cm (Makostev) type of bird reflex bird, the effect does not seem very good; also need to pay attention to the mirror axis accuracy, and coating oxidation problems. In short, the basic principles of telescopes and bird-watching telescopes are the same. Apart from these differences, other differences include:
1. Most of the mirrors used in astronomical telescopes can communicate with each other, and bird-watching mirrors are mostly self-contained.
2. Astronomical telescopes usually have a higher magnification (100 or more) than eyepieces, and a bird's-eye mirror is usually no more than 70 times.
3. Because the astronomical binoculars observe celestial bodies close to infinity (in terms of focusing), the recent imaging distances of some astronomical telescopes are limited (usually added to take care of the problem), and bird watching is less This problem
4. Some birdwatchers have a waterproof design
5. Astronomical telescopes usually have finderscope designs, making it easier to find targets
6. The bird mirror is usually designed with a positive prism in the lens barrel. The astronomical telescope is usually attached with a zenith prism (up and down, right and left, upside down), but there is a forward mirror for purchase.
7. The focus is slightly different