Section 3
Lenses
Book
Version 3
By Boundless
By Boundless
Boundless Physics
Physics
by Boundless
5 concepts
![Thumbnail](../../../../../../figures.boundless-cdn.com/16533/square/figure-2026-06-01.jpeg)
Thin Lenses and Ray Tracing
Ray tracing is the technique of determining the paths light rays take; often thin lenses (the light ray bending only once) are assumed.
![Thumbnail](../../../../../../figures.boundless-cdn.com/16536/square/figure-2026-06-07.jpeg)
The Thin Lens Equation and Magnification
The thin lens equation relates the object distance do, image distance di, and focal length f.
![Thumbnail](../../../../../../figures.boundless-cdn.com/16594/square/figure-27-06-01.jpeg)
Combinations of Lenses
A compound lens is an array of simple lenses with a common axis.
![Thumbnail](../../../../../../figures.boundless-cdn.com/16537/raw/lens1.jpg)
The Lensmaker's Equation
The lensmaker's formula is used to relate the radii of curvature, the thickness, the refractive index, and the focal length of a thick lens.
![Thumbnail](../../../../../../figures.boundless-cdn.com/16558/square/figure-2026-06-02.jpeg)
Refraction Through Lenses
Because the index of refraction of a lens is greater than air, a ray moves towards the perpendicular as it enters and away as it leaves.