Focal Width Length Calculator

Focal Width Definition

A focal width, also commonly used to be the same as focal length (or focal distance), is a term that describes a measure of how strong a lens or mirror converges or diverges light when it hits the curvature of the lens. A positive focal width indicates that the lens will converge light, and a negative focal width will indicate that the lens will diverge light. The positive and negative come from which side of the lens the focal point is on. The focal point will be to the left of the lens for diverging light and to the right for converging light.