| A refracting telescope uses a lens as its objective to | | | | planet Jupiter and its moons. |
| form an image. The refracting telescope was | | | | The Keplerian Telescope, invent by Johannes Kepler in |
| designed for used in a spy glass, but is also used in | | | | 1611 improves upon Galileo's design. The Keplerian |
| other devices such as binoculars and telephoto | | | | Telescope uses a convex lens in opposition to Galileo's |
| camera lenses. | | | | concave lens. This allows for a broader field of view |
| There are two principles to a refracting telescope, an | | | | and greater eye relief. However, the view is |
| objective lens and an eyepiece. These two principles | | | | introverted. |
| gather more light for the human eye and helps to | | | | An achromatic refractor is a refracting lens which was |
| focus and present it in a brighter, clearer, and magnified | | | | invented in 1733. The design over came the need for |
| virtual image. A refractive telescope bends light to | | | | very long focal lengths and used two pieces of glass |
| cause parallel light rays to converge at a focal point. | | | | with different dispersion to limit the effects of |
| Galilean Telescopes are refracting telescopes. Galileo | | | | chromatic and spherical aberration. Each side of each |
| came up with the design in 1608 and uses a convex | | | | piece of glass is ground and polished, at which point |
| lens and a concave eyepiece lens. The Galilean | | | | the two pieces of glass are assembled together. |
| telescope magnifies objects up to thirty times. The | | | | Achromatic lenses bring two wavelengths together |
| Galilean telescope was the first telescope to see the | | | | and focus them on the same plane. |