- You can make a miniature image of a distant object by using a single converging lens
- Rays of light enter the lens, and because of the lens shape they are refracted first on entering the lens and again on leaving
- Refraction is when a ray of light bends as it passes at an angle from one material to another
- A horizontal line passing through the centre of the lens is called the principal axis
- The distance from the centre of the lens to the focus is called the focal point. The longer the focal length of a lens, the larger the real image that the lens produces of a distant object will be
Focal length:
- A lens which surfaces aren't strongly curved and that is thin has a long focal length and low power
- A lens with strongly curved surfaces which is fat has a short focal length. It bends the rays of light more, so has high power.
power (in dioptres)= 1 / focal length (in metres)
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