13.1 (Lenses and Formation of Images) -Muneeb & Josh

Chapter 13.1 Lenses and the Formation of images

By: Muneeb & Josh

Everyone see's the world through a lens, even if you do not have glasses or any type of vision aid. You still see the world through the lenses in your eye.

There are two basic lens shapes, the first one is a converging lens, it is when parallel light rays converge through a single point after refraction through the lens.
A converging lens brings parallel light rays together through a focus after refraction

The second basic lens shape is the diverging lens, in a diverging lens, parallel light rays diverge after refraction from the lens.
A diverging lens spreads parallel light rays apart after a refraction so it looks like they have come from a virtual focus.

In a diverging lens, the principal focus is on the side of the parallel light rays, the focal point is where all the refracted rays meet, and since the light rays diverge after refraction, they are extended to behind the lens, meeting at a focal point on the principal axis. 

Terminology 

1. The center of the lens is called the optical centre (O) 

2. The line through the optical centre that is perpendicular to the dashed line of the lens is the principal axis

3. Light rays parallel to the principal axis converge through a single point on the principal axis is called the principal focus (F)

4. The distance between the focal point and the optical centre is known as the focal length (OF)

Watch this video for more information on lenses and the formation of images.


https://www.youtube.com/watch?v=OSUGRvYwxw8