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## Light passing through convex and concave lenses ### Convex Lens A **convex lens** is thicker in the middle than at its edges. Rays of light that pass through a convex lens **converge** or **join**. A convex lens is also known as a **converging lens**. ![Diagram showing a convex lens](https://...

## Light passing through convex and concave lenses ### Convex Lens A **convex lens** is thicker in the middle than at its edges. Rays of light that pass through a convex lens **converge** or **join**. A convex lens is also known as a **converging lens**.  - The diagram above shows a convex lens with an object placed beyond the focal point. When the rays of light pass through the lens, they converge at a point called the **real focus**. The image formed is real, inverted, magnified and the image size depends on the position of the object relative to the lens. The image is enlarged when the object is between F and 2F. When the object is beyond 2F, the image formed is smaller. - The distance between the optical center (O) of the lens and the focus (F) is called the **focal length** (f) of the lens. ### Concave Lens A **concave lens** is thinner in the middle than at its edges. Rays of light that pass through a concave lens **diverge** or **spread out**. A concave lens is also called a **diverging lens**.  - The diagram above shows a concave lens with the object placed beyond the focal point. In this case, the rays of light diverge after passing through the lens. These diverging rays, when produced backwards, meet at a point called the **virtual focus**. - The image formed is virtual, erect, diminished and always formed between the lens and the object. The **focal length** (f) of a concave lens is negative.