Question

The image of an object is obtained with a camera having a small aperture (Fig.). The depth of the camera EC is 20 cm, its distance CD from the object is 20 cm, and the diameter of the aperture C is 1 mm. Determine whether, under these conditions, details on the object 2 mm in size can be distinguished.

Answer 1

For the given positions, the image of each point of the object will be a circle whose diameter may be determined from the ratio (Fig.)

Consequently, it is impossible to distinguish details smaller than 2 mm for the given positions, since the circles of light which form the image of each point of this detail will be superimposed on one another.