Question

The focal length of a lens in a photo camera is 10 cm. The fixed distance between the lens and the film is 11 cm. If an object is clearly focused on the film, how far must the object be from the lens? What is the len's magnification?

Answer 1

The magnification of the lens is
m& = - h2/h1 = - (d2-f)/f = -1/10.