How does a photograph become a photograph?
- You press down on the shutter release
- This then controlls the aperture which when changed controlls the amount of light let in and then open and closes the shutter
- The light thenn goes inside the camera and hits the back in which there is chemicals ie roll of film etc
- It then produces an image upsidedown which then becomes a photo.

Without light photography wouldnt be possible.

History Of Photography

http://www.dipity.com/jazminchevannes/History-Of-Photography/