Using Lenses

Using Lenses

1. We can draw ray diagrams to find the image that different lenses produce with objects in different positions.

2. The line through the centre of the lens and at right angles so it is called the principal axis. Include this in your diagram.

3. Ray diagrams use three construction rays from a single point on the object to locate the corresponding point on the image:

   • A ray parallel to the principal axis is refracted through the principal focus.
     • A ray through the centre of the lens travels straight on, without refraction.
       • A ray through the principal focus is refracted parallel to the principal axis.