How does a camera create an image?

Question

How does a camera create an image?

Answer 1

Lenses focus light on an image plane.  That image plane used to be a film containing light sensitive compounds (Ag compounds).  When the exposed film was chemcially processed, the areas that did not get much light become dark, areas that got more light remain transparent.  This makes the "negative".  Light is then shown thru the negative onto special light sensitive paper.  After more chemical processing, it produces a positive, a picture.  

In digital cameras, you still need a lens.  The image plane is made up of many tiny light sensors (when they talk pixels they are talking about the number of light sensors).  The light detected at each pixel creates an electrical signal.  A computer (inside the camera or inside the printer or inside the computer) converts those signals into an image.

hope this helps.