Telescope tube of a reflector is shorter than that of a refractor of the same diameter which reduces the cost of the tube, and they are easier and cheaper to build large, They are also easier to mount because the back of the mirror can be used to attach to the mount. Reflecting telescopes are not subject to the chromatic aberration because the reflected light does not disperse according to the wavelength, and all the wavelengths will reflect off the mirror in the same way. The reflectors are used not only to examine the visible region of the electromagnetic spectrum but also to explore both the shorter- and longer-wavelength regions adjacent to it, The primary mirror reflects the light back to a focus instead of refracting it, The primary mirror usually has a concave spherical or parabolic shape, as it reflects the light, it inverts the image at the focal plane. Prime focus telescopes have no secondary optics and the observer or camera observes the image from near the focal point, Coude telescopes use a convex secondary mirror like a Cassegrain and an angled mirror like a Newtonian reflector to move the light rays to a focal point away from the telescope, This arrangement is useful when optical equipment is being used that is too heavy to mount directly on the telescope. There are many types of reflectors that solve the issue of where to focus the light in different ways such as Cassegrain reflectors which have a convex secondary mirror and a hole in the middle of the primary mirror. Reflecting telescope uses a mirror to collect the light instead of a lens, This overcomes the problems inherent in supporting the lens in a refractor telescope and the light losses due to the light passing through thick pieces of glass, and the mirror of a reflector is at the bottom end of the telescope tube.Ĭurved mirrors can bend the light and make parallel light rays converge to a focus, This focus is directly in the path of the incoming light, So, there are several ways of making images from the mirror visible, One is called a Newtonian reflector where a flat mirror is used to point the light rays out to an eyepiece. Reflecting telescopes use the mirrors instead of lenses to focus the light, The convex mirror is used to gather the light and reflect it back to a focal point to get the light out of the telescope, another mirror is used to direct the light to an eyepiece.
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