Question

what is an pinhole camera, tell a principal of it? ​

Answer 1

Pinhole cameras rely on the fact that light travels in straight lines – a principle called the rectilinear theory of light. This makes the image appear upside down in the camera. One thing that inspires many pinhole photographers is the craft of building their own cameras.

Answer 2

Answer:

Pinhole cameras rely on the fact that light travels in straight lines – a principle called the rectilinear theory of light. This makes the image appear upside down in the camera. One thing that inspires many pinhole photographers is the craft of building their own cameras...