Question

Describe how a pinhole camera, or camera obscura, works. Why is the image upside down?

Answer 1

Pinhole cameras rely on the fact that light travels in straight lines i.e., a principle called the rectilinear theory of light.This makes the image appear upside down in the camera.

A small pinhole generally produces sharper images than a larger one.However,if the pinholes is too small,light waves may be scattered slightly at the edges of the pinhole and cuase distortion or loss of focus.

Smaller holes also increase exposure times ,sinc they will let less light inti the camera.