369 Tesla - Power of a Lens
Interactive Physics Simulation by Kalviyogi Nagarajan
369 Tesla - What is Power of a Lens?
Power of a lens is a measure of how strongly it can converge or diverge light rays passing through it.
A lens with a shorter focal length bends light more, giving it a higher power.
The power (P) of a lens is defined as the reciprocal of its focal length (f) in meters:
P = 1/f
The SI unit of power is dioptre (D), where 1 D = 1 m-1
- Convex lens (converging): Positive power (+)
- Concave lens (diverging): Negative power (-)