What you need to know to Buy the Best Telescope (part 2)Apexeloptic
A good pair of binoculars is a long-term investment, which is why it’s best to buy one you’ll always want to use, rather than one you’ll put aside and forget about. Before you decide to buy a telescope, you should read this guide on what you need to know to buy the best telescope.
What you need to know to Buy the Best Telescope (part 2)
(1) Telescopes can be roughly divided into hand-held and non-hand-held telescopes.
Hand-held telescopes, whether military or civilian, are virtually the same multiple. And there is a common standard multiple, that is 7 times, 8 times, 10 times, these three standard multiples. This is a lot of experience, the most suitable for handheld multiples, it can be said that all modern military handheld telescopes and most civilian telescopes are these three standard multiples.
It should be noted that there are a lot of inferior products, and parameters are random marks. And the table type of telescope, because there is a tripod, so the multiple limits are less, can be higher. However, such products also have their disadvantages, that is to use a tripod, not handheld use.
(2) Be rational about prices
You can’t have anything good with a telescope that’s too cheap. But the more expensive the telescope, the better it is. Regardless of the objective aperture and finished product parameters, refracting telescope mainly depends on lens materials and coating process. The coating function of refractors is to reduce light reflection, reduce chromatic aberration and increase light transmittance.
What every lens passes elaborate coating is a good mirror, accordingly, the stand or fall of coating technology is affecting the price of the mirror to a great extent. But no matter how good the coating is, it is impossible to achieve perfect, only better, not the best, so, if there is no special need, a mid-range mirror is enough to play with. Apexel’s telescopes are not expensive. You can buy a pair of telescopes for a few tens of dollars to meet your basic needs. You can check out the website.
(3) Identify whether optical elements are genuine optical elements
The telescope market is mixed, and the development of telescope materials is changing with each new day. Before 2000, inferior telescope manufacturers used substandard optical components to replace them, and after 2001, resin lenses emerged as a rookie, with lower costs and further reduced optical performance.
The prism of the optical element identification method, because of the large volume of telescope prism, is difficult to manufacture with resin, so basically, we still use a shoddy method. It is also easy to identify, turn the telescope upside down, and look at it from the objective end to the bright open place. If there is a black broken line or black stain found inside, it means that the telescope is assembled with waste. The black broken line and black spots are broken ridges and broken points of the prism.
Lens identification, carefully look at the eyepiece of the telescope, if it is not light blue but white (actually colorless), that the eyepiece is not coated, why not coated? Because it is pressed with plastic resin, put in the coating machine before coating in the preheating stage of the coating material was baked in high-temperature deformation or melting.
(4) Type of mirror
Reflectors are mainly divided into Newton-type and Cassegrain type, Cassegrain type is rare in the hands of enthusiasts, and the price is more expensive. Newton-type reflector eyepiece at the front end, the tube is not so easy to operation, maintenance is relatively complex, such as correction optical axis and coating are more difficult, the biggest advantage is cheap, but it is also the easiest homemade type of telescope, so has been very popular in the amateur astronomy, domestic there are polished mirror lens assembly and Newton.
At present, the mainstream Newton mirror sold on the market is a large aperture and small focal ratio. This kind of telescope has strong light strength and a large field of view, which is very suitable for the visual observation of deep space celestial bodies. Moreover, the design level of the eyepiece has been substantially improved compared with 20 or 30 years ago. Ultra-wide angle eyepiece with a field of view over 80 ° is used to obtain satisfactory image quality in the full field of view of mirrors with a relative aperture larger than F/4.