For thin lens, when image distance equals object distance (|v| = |u|),…

Question

For thin lens, when image distance equals object distance (|v| = |u|), object position is:

Accepted Answer

A. At 2f (object and image both at 2f)

For convex lens, |v| = |u| occurs at u = 2f.
Then v = 2f, m = -1 (same size, inverted, real).
Useful for image relay systems.

Answer

At f

Answer

Half of f

Answer

At infinity

For thin lens, when image distance equals object distance (|v| = |u|), object position is: