The Lens Equation

The Lens Equation

1. The following is the lens equation that relates the object distance (u), image distance (v) and the focal length. $1 u + 1 v = 1 f$
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

Linear Magnification

The linear magnification is a quantity that indicates the ratio of the height of the image to the height of the object.

$m= v u = h i h o$
m = linear magnification
u = distance of object
v = distance of image
hi = heigth of image
ho = heigth of object