In the Kodak Customer Service Pamphlet AA-26, Optical Formulas and Their Applications, the near and far limits of the depth of field (how close or how far away an object can be placed and still be in focus) are given by

In these equations, θ represents the angle between the lens and the “circle of confusion,” which is the circular image on the film of a point that is not exactly in focus. (The pamphlet suggests letting θ = 1/30°.) L is the diameter of the lens opening, which is found by dividing the focal length by the f-stop. (This is camera jargon you need not worry about here.) For this problem, let the focal length be 50 mm, or 0.05 m; if the lens is set at ƒ/8, then L = 0.05/8 = 0.00625 m. Finally, u is the distance to the object being photographed. Find the near and far limits of the depth of field when the object being photographed is 6 m from the camera.

Transcribed Image Text:

W₁ u²(tan 0) L + u(tan 0) and W2 = u² (tan 0) L - u(tan 0)*