Principles of monocular telescopes |
Posted: April 9, 2020 |
Telescope is a telescope used by astronomers to study celestial objects. There are 2 important properties which are The ability to combine light - telescopes can combine more light than the human eye. Helps to see low-light objects such as nebulae and galaxies. Magnification - The telescope helps to enlarge the size of the image. Make the object more visible, such as holes on the moon, planets, stars, etc. An important feature of a monocular is a convex lens that is responsible for fading light at the focal point. We call the distance between the center of the lens and the focal point. If using a convex lens to look at objects that are closer than the focal length The convex lens will help to enlarge the image. If using a convex lens to look at objects that are farther than the focal length The convex lens will help to combine the light Then turn the image upside down. Total lightOne of the most important properties of telescopes is "Light-gathering power" telescopes help astronomers see distant objects such as nebulae, cluster clusters and galaxies. Which cannot be seen with the naked eye Because light travels from a very long distance The intensity of light therefore decreases. The telescope's lens has more light than the human eye. Therefore has more power However, we are unable to determine the total power of the lens to be specific. But determined by comparing the ratio between the two lenses. We can change the magnification of the telescope to be suitable for use as in Table 1 by choosing to use an eyepiece with a focal length more or less. However, in practice, when the magnification is doubled, the brightness of the image will Reduced by 4 times the size of the objective lens is the maximum magnification limiter Using a high magnification while the objective lens is too small to produce low quality images and too dark.Usually the maximum magnification that actually works is approximately 50 times the diameter of the objective lens, which is in inches. For example, a camera with a diameter of 100 millimeters or 4 inches will have a usable magnification of not more than 50 x 4 = 200 times. In addition, although the objective lens is very large But when using magnification more than 400 times, it will also expand the air current The resulting image will be blurred, shaking like watching fish in a fast-flowing stream. For this reason, scientists built large telescopes on the tops of high mountains that have thin air. Or send a monocular into space for a clear image Since there is no atmosphere as a barrier to the path of light at all. Read this: www.marketwatch.com/press-release/starscope-monocular-review---new-state-of-the-art-device-2020-03-03 for details. Focus ratioThe Focal ratio is another important feature of telescopes. Which is the ratio between The diameter of the object lens and the focal length of the objective lens Which is usually shown with the letter f / on the lens. For example, a lens with a diameter of 100 millimeters, a focal length of 500 millimeters with a f / 5 focus ratio, a lens with a diameter of 100 millimeters, a focal length of 1000 millimeters with a f / 10 focus ratio. The telescope design is suitable for use. Depending on the selection of objective lenses with the following focus ratio Convex lens or concave mirror with f / low (f / 3 - f / 7) has a wide cone Give low magnification But make the image brighter Suitable for viewing large objects with low brightness, such as galaxies. Convex lens or concave mirror with f / large (f / 8 - f / 15) with a narrow cone Give high magnification But the picture is not bright Suitable for viewing small objects that are very bright, such as planets. Do not use the telescope to look at the sun. Without absolutely quality solar filters As it may cause blindness
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