Refracting telescopes don’t use mirrors. Instead, this type of telescope has an objective lens permanently attached to the front end of a tube. The light from stars or other celestial objects passes through the lens and when it does, it gets bent, so that it forms an image at a focal point near the back of the telescope. The image is made even clearer as it passes through the eyepiece.
The distance from the objective lens to the image at the back of the tube is called the focal length. The lens that you look through at the front of the telescope is called an ocular or eyepiece. The tube helps to protect the lens from getting dirty or gathering any moisture on it.
Who was the first person to use refracting telescopes?
Galileo Galilei was an Italian astronomer from the 1600’s and he first used this type of telescope in the year 1609. The telescope he used was said to be less than 2 inches.
These telescopes can range in size from 60 millimeters to the world’s largest telescope, which is 1 meter in size. This telescope is located at the Yerkes Observatory in Williams Bay, Wisconsin and it was built in 1897.
This type of telescope used to be the telescope design of choice among astronomers, but in recent years, more and more astronomers are choosing reflecting telescopes. Refractors have a higher degree of error and can distort images more easily.
Even though refractors are not as popular as reflectors these days, they were the first type of telescopes used by ancient astronomers.
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