#NEWTONIAN REFLECTOR INSTALL#

f/10, to reduce chromatic aberration), Newtonian telescopes can confidently be designed with optics of up to f/4. Whereas refractors tend to have smaller aperture ratios (e.g. Newtonian reflectors come in a relatively wide range of aperture ratios. This means that the focal length is 10 times as large as the aperture. A telescope with 100/1000mm has an aperture ratio of f/10. The aperture ratio of a telescope is the relationship between its aperture and focal length.

It is hence important to rely on well-known brands. Equally important are the quality and reflectance of the mirrors - which can be very different, depending on the telescope. But that is not the only criterion for producing a good image. This means that the problem of colour fringing around bright objects is avoided with Newtonian reflectors. The advantagesĪs opposed to a lens telescope, a reflector has no lenses. Focusing takes place by turning a focus wheel on the focuser so that the eyepiece is moved towards or away from the telescope tube. The light enters the focuser here, into an eyepiece can then be inserted for observing. This is a plane mirror which deflects the light beam by 90°, hence directing it out the side of the tube. In order to prevent the image to be focused in front of the tube opening (and hence obscured by your head!), there is a secondary mirror inside the top of the tube. This mirror reflects the light back upwards. At the lower end there is a primary mirror that is either spherical or parabolic in configuration. Light first enters the top of the telescope tube. Just imagine: A telescope that was originally designed in 1668 is still one of the most popular and best-selling amateur telescope designs today, in the age of smart phones and iPads!

#NEWTONIAN REFLECTOR INSTALL#

Newton's idea was to install a flat deflecting mirror into the telescope tube. Actually, Newton was further developing an existing telescope design, as the physicist Zucchi had already constructed a telescope in 1616 which employed a mirror.

Isaac Newton first built this telescope in 1668. The principle is straightforward yet ingenious. The Newtonian reflector is the classic mirror telescope design.