Pinhole Camera 

A pinhole camera has three essential parts: a light-tight box, a door, and a small hole.

A pinhole camera is a camera simply made with a light-tight box and a pinhole at one end.  The first pinhole camera was invented by Alhazen in 1000 AD, and there have been many different variations of the pinhole camera ever since then. Although a pinhole camera does not have a lens, the pinhole on the side of the camera acts as one since it allows light to enter to form the image. Pinhole cameras create images without the use of a lens


  

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How does it work? 

The pinhole in a pinhole camera acts as the lens. Because light travels in a straight line, light from the object passes through the pinhole which causes every point emitting light in the scene to form a small point on the paper or film, so the image is clear. Once the light passes through the pinhole, the camera produces an inverted and upside down image of the object on the screen.