What are the types of telescopes?

Yes (limited to farsightedness and nearsightedness, not astigmatism). Because telescopes and glasses are spherical lenses with a certain power (astigmatism is cylindrical lenses). But the "power" of the telescope is too large, and because it is a lens group, it has a limited focusing range.

The role of a telescope is to change the perspective of the target. It makes the image on the retina larger in size. What originally fell on one visual cell fell on more visual cells. Should be able to see better.

In fact, it is possible that the quality of the telescope is not good, which makes the image large and blurry. It's hard to say how effective it is.

Yes, people with myopia can see objects clearly by adjusting the focal length even if they use a telescope without glasses.

But it won't be clearer, just like what you see with normal vision.

You're trying the wrong way.

This means that you won't be using your telescope yet.

How can anyone hold a telescope and look at an object within 15 centimeters?

The design of the telescope.

There is a minimum photopic distance.

High-end telescopes.

For example, a mirror like Zeiss in Germany.

The twin barrels cost more than 10,000 yuan.

The nearest photopic distance can be very small.

Around 1 2 meters.

If you look at this example, you can't see anything clearly.

Those low-end telescopes.

For example, a fake Russian mirror for a few hundred dollars.

The nearest photopic distance is generally more than 10 meters.

It's too close to see clearly.

You take it outside and try it.

There is another possibility.

You astigmatism.

<> optical stool astronomical telescopes are further divided into reflective, reflective and catadioptric astronomical telescopes.

As the name suggests, a refracting telescope uses the principle of refraction of light to concentrate light rays. Early telescopes generally used a convex lens, but this introduced a chromatic aberration problem.

The dispersion of light knows that light of different frequencies has different refraction angles after passing through the lens, so when the light passes through the refractive telescope, there will inevitably be chromatic aberration, which is embodied in the purple color at the edge of the object.

In order to solve this problem, people use a variety of lens combinations to reduce chromatic aberration to a certain extent, and now the chromatic aberration of good refracting telescopes has been reduced to a negligible level. But because of the use of a variety of lenses, it is relatively high. The advantage is that the imaging is sharp, which is conducive to astrophotography.

Land Bridge Sail. Reflecting telescopes use the principle of light reflection to concentrate light. Since the reflection principle is used, there is no problem with chromatic aberration. However, compared to refraction, the objective lens of a reflecting telescope has a secondary mirror in addition to the primary mirror, which generally blocks the light path.

In addition, the imaging of reflective telescopes is very sensitive to the optical axis and accuracy, and the lens barrel is open, so it is easy to enter the dust, and the optical axis needs to be adjusted, which can be a bit difficult for novices. But its advantage is that it is cheap, and the caliber can be made very large.