A camera with a 50.0 mm lens is designed to focus from 1.00 m to infinity.What is the distance of travel of the lens with respect to the film plane over this range of focus?
A) 50.0 mm
B) 52.6 mm
C) 47.4 mm
D) 5.30 mm
E) 2.60 mm

Question

Quizplus · Accepted Answer

The lens formula is 1/f = 1/v - 1/u. For infinity, v = f = 50 mm. For 1 m, u = 1000 mm, and solving gives v ≈ 52.6 mm. The travel distance is 52.6 mm - 50 mm = 2.6 mm.

A Camera with a 50