Under the premise of using both hands, how should a beginner choose to be the first mirror in his own way as a beginner? What are the principles that need to be followed? Here is a summary, to buy a mirror reference for friends who are a bit hesitant.
Even for those who often use binoculars, I think the rate of holding double vision is no more than 10 times. For beginners, the principle is very clear and low, and I can even say that if a beginner wants to buy an entry mirror, it is 6 to 8 times the scope, and other rates can not be considered.
The rate of double expectations is sometimes the only technical index that beginners consider when buying glasses. First, how many times do I have to ask? What? Only 8 times? What's the use of it? I want 20 times that? Ah? 100 times more? Excellent! ......
We often emphasize that the higher the rate is, the more darker you will get. Ignoring another decisive factor, that is, over 12 times, even for skilled users of telescopes, it will feel sway instead of catching targets.
Another point for beginners is the index of visual field -- the field of view. The higher the ratio, the narrower the angle of the field will be. About my understanding and description of the corner of the field,
For beginners, they often encounter such a situation that they can see a target far away and want to see it. But picking up binoculars, we can't find it back and forth. This phenomenon has a great relationship with the angle of the field of view. In order to make it easier for beginners to find what they want to see, as an entry mirror, I think the ideal field of view should be above 8 degrees (the worst, and 7.3 degrees).
From beginners to telescopes, they need time and money to accumulate. About money, it's not on the table for the time being. But time is an absolutely necessary factor. When I came into contact with the binoculars, I sometimes stood in the window for hours a day, so that the details of a variety of binoculars could be deeply printed in the brain to pick up a telescope and immediately identify its advantages and disadvantages.
As a beginner, if you want to understand the mysterious mood of telescope very quickly, the first thing to do is to spend some time watching and using the telescope. There are many shopkeepers who sell telescopes, but they rarely use telescopes. Don't see him sitting in a telescope every day, nor how much he knows about the telescope (except for the price).
In order to achieve the purpose of using Russian telescope frequently, I suggest beginners not to buy too big and too heavy products. It's better to be 32mm caliber. The caliber is too large to carry around, and the time and opportunity to play will be reduced, and the growth rate of beginners can not be raised. The aperture is too small (for example, 21mm caliber), usually because the light aperture is too small, the imaging is dark, it is difficult to realize the color enjoyment that the telescope brings to the eyes. At the same time, the dual field of view of 21mm caliber is relatively small, which is also not good for beginners.
3 "structural form
In general, the prism is mainly different. It's Paul prism and ridge prism. As a rule of thumb, we prefer to choose straight looking pairs because their shape is lighter and more convenient to carry. However, considering that when we purchase the introductory mirror, we will not consider expensive telescopes, generally consider cheaper products.
In cheaper products, the image quality of Paul mirror is obviously better than that of straight mirror under the same price condition. So I suggest that when beginners purchase the introductory mirror, they will consider Paul's prism's double look better.
4 Avoid specific lenses (refusing binocular focusing, refusing super small field of view, refusing big dummy).
There are a lot of telescopes dedicated to one occasion, such as military mirrors, astronomical mirrors, navigational mirrors, bird watching mirrors, and so on. We know that even those who use binoculars will feel inconvenient in binocular focusing, let alone beginners. There are 750 suitable for the star, the navigation mirror and so on, mostly the form of double eye focus, for novice, it is not convenient to use, in addition, it is also very heavy, not conducive to long time to carry, play. There are also special glasses 10X42, 8x56 and so on. One of their common features is that the center resolution is high, but the field angle is narrow, which is not good for the beginners to look for the desired goal.
And that's the product that's doubled. Is it absolutely attractive for beginners? But as a matter of fact, because of the narrow field of view, the drift of the field of view (which becomes blurred), the color difference, the blurred field of the field of view, and so on, the old hands of the binoculars have no preference for double looking.
Don't be too cheap. Too cheap a mirror can't let you experience the visual enjoyment brought by your double eyes, but it will produce no big mistake. So, I suggest that the introduction of the mirror is not too cheap. How much is it? It's better for everyone to make decisions based on his own income. I won't say that specific figure here.