Why do objects look distorted when photographed with a wide angle lens?
This is because the size of the image of an object depends on the distance the object is from the lens. This is not a defect in the lens—even pinhole cameras with no lens at all exhibit this perspective effect. For image calculation purposes, think of the lens as being a geometric point at one focal length in front of the film, and centered over the center of the film. (If the lens is not focussed at infinity, the distance from the film gets larger.) Then the image of a subject point can be found by drawing a straight line from the subject point through the lens point and finding its intersection with the film. That line represents one light ray. (Diffraction and out-of-focus conditions have been ignored here, since they are irrelevant to this effect.) If you do this, you’ll find that the image of a nearby object will be larger than the image of the same object farther away, by the ratio of the distances. You’ll also find that any straight line in the subject, no matter at what angle
