Further Physics - Observing the Universe - Lenses and Telescopes
In a convex lens, also called a converging lens, rays of light are bent inwards as they pass through the lens. If the rays of light entering the lens are parallel, the rays will be brought to focus at a focal point.
A more powerful lens has a more curved surface and a shorter focal length than a weaker lens. The power of a lens is measured in dioptres and can be calculated using the following formula:
Power (dioptre) = 1/Focal Length
In a convex lens, also called a diverging lens, rays of light are bent…