CEMASTEA has variety of innovations and in this demonstration, a national trainer is explaining to students how a Pinhole camera operates.

A pinhole camera is a simple camera without a lens and with a single small aperture, a pinhole – effectively a light-proof box with a small hole in one side. Light from a scene passes through this single point and projects an inverted image on the opposite side of the box.

A pinhole has the ability to function like a glass lens because it excludes all light rays which are not reflecting off the subject that the camera is pointed at.  When light hits an object, it is scattered in all directions; this is why the object is visible from any angle.  If all this light was entering a camera and hitting the film, no image would be produced.  The light needed for a photo has to be aligned to make a focused image.  The pinhole excludes light rays from all irrelevant angles and only allows through rays which are almost perfectly aligned from the subject through the pinhole to the film. 

For example the above image show a clear explanation on how the inversion occurs. The yellow lines are light rays.  Note that they cross at the pinhole and produce an inverted image. In our case, the arrow will be viewed as inverted, that is, arrow facing up.