Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
The focal point is the specific point on either side of a lens or mirror where parallel light rays converge or appear to diverge from.
Related terms
Lens equation: The mathematical relationship between an object's distance from a converging (convex) or diverging (concave) lens, its image distance, and their respective focal lengths.
Principal axis: An imaginary line that passes through both sides of an optical device (such as lenses or mirrors), perpendicular to their surfaces.
Ray diagram: A visual representation used to determine how light rays interact with lenses or mirrors and predict where images will form.