5.4.7 Lens Formula

The Lens Equation

  1. The following is the lens equation that relates the object distance (u), image distance (v) and the focal length.
  2. When using the lens equation to solve problem, it's important to note the positive negative sign of u, v and f.
  3. Table below give the conventional symbol and sign for u, v and f.


Positif
Negatif
u
Real object
Virtual object
v
Real image
Virtual image
f
Convex lens
Concave lens