Refractor telescopes are a device which uses lenses to form an image. Refractor telescopes were first created by Hans Lippershey in 1608 but were later improved by Johannes Kepler where his design was to have two convex lenses. A refractor telescope contains a long tube that can be made out of metal, plastic or wood. The objective lens which is a combination of glass and the eyepiece which is a second combination of glass lens.
The behaviour of light passing through different media
Refraction is the bending of light when passing through different materials (mediums). When light passes through different mediums, the light starts off travelling in a straight line but as soon as the light hits the boundary the light bends in the medium and continues…show more content… Refraction only happens at the boundary which can cause visual distortions when light changes from one medium to another as it travels from the object to the eye. This can happen when you see a pen or pencil placed in a glass of water. When you look through the side of the glass, you can see that the pencil appears to be split. This is because the light travels from water to air and vice versa and changes mediums meaning it goes through refraction. In order for refraction to occur, the light ray needs to change speed when crossing the boundary and the light ray needs to approach the boundary at an angle, because refraction doesn't occur when the light ray is approaching straight on. The change in speed causes the change in direction at the boundary. The light ray to change from one direction or another is determined by whether the ray speeds up or slows down when crossing the boundary. The speed of the light ray is determined by the mediums properties. The light rays speed depends on the materials (mediums) optical density. Optical density is the measure at which a material transmits light or other electromagnetic radiation. An…show more content… The image will be located on the object side of the lens because if we were to extend the refracted light rays back and make them intersect it will create the image location. The image is said to be virtual because the light appears to come from the image location to the observer’s eye. The image will also be upright and reduced in size.
Simple Refracting Telescope
The sum of the 2 focal point lengths of the lenses will be the distance between the two lenses. A simple refracting telescope is made up of two convex lenses which produces an inverted final image. The objective lens produces the inverted image and the eyepiece magnifies the image for the observer to see. The light rays travel through the objective lens to create the real image to be magnified by the eyepiece lens.
Complex Refracting telescope
The sum of the 2 focal point lengths of the lenses will be the distance between the two lenses. The objective lens (convex lens) creates the real image and the eyepiece lens (concave) produces the magnified upright version of the image which the observer can see. The light rays travel through the objective lens to create the real image to be magnified by the eyepiece lens. On the diagram to the right it shows that the eyepiece is a concave lens and is small for the magnification of the image that is produced by the larger lens in the diagram (the convex lens). The light enters