Optical Telescopes

Optical Telescopes are able to collect significantly more light than the human eye, the larger they are the more light they are able to capture, which then forms and image of distant objects for the eye to see. When we turn a telescope to the night sky an optical telescope gathers and focuses light allowing us to see distant, faint stars and astronomical objects, well beyond what our eyes are capable of.

The invention of the optical telescope literally thrust humanity into a new universe. It changed our perspective on the universe completely, allowing the Moon and Planets to be observed and understood more closely, and for a whole host of new stars to be visible to the eye. Essentially, a more detailed, higher-resolution perception of the Universe.

There are two basic designs of optical telescopes: a refracting telescope and a reflecting telescope. They both fundamentally gather light from a wider area of the sky than the human eye is capable of, and then focus that light towards the eye, but they do this in fundamentally different ways. Refractors bend that light with a lens to focus it on the eye, while reflectors focus that light by bouncing it off a specifically designed mirror.

Telescopes gather light from an area across the sky by design. Both types of optical telescopes have what is called an objective — the primary light-gathering mechanism of the device — which in refracting telescopes is the main lens (fashioned with optical grade glass) and in reflecting telescopes is a mirror.

While optical telescopes can differ in design, they share the same purpose: to gather more light that can be focused onto the eye to extend our optical perception. This ability of a telescope to collect light is called its light-gathering power. It’s light gathering power is proportional to the area of the circular collecting surface, the main lens or the main mirror that gathers light, the square of the diameter of the collecting surface that we call aperture. Whenever the size of a telescope is referenced, it is a description of the size of its aperature. The larger the aperture the more starlight that can be captured, the brighter the objects are because of that extra light, the clearer the picture and the further that we can see — with our eyes through an eyepiece, by taking a photograph, or the image can be recorded and processed electronically.

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