How is lens power related to focal length?

عدسے کی طاقت اور فوکل لمبائی کا تعلق کیا ہے؟

Solution & explanation

P = 1/f with f in metres; unit dioptre, D = m⁻¹. Converging lenses have positive and diverging lenses negative power in this convention.

Independent study material · English-medium textbook p. iii–iv · Original book ↗