Digital Photography Technique: Light and Image VS Vision using Cheap digital cameras

To create a good picture two things are necessary: a more or less clear idea of what you're going to do and the intelligent use of technical mediums to achieve it. After all, photography is very related to our most developed sense, sight, but is also a reproduction method of great technical complexity. The various technical matters are interdependent variables which are present at the time of creating any picture. "Intelligent usage" is a conscious application of our technical knowledge to be able to register an image the way we want it to appear. Our knowledge of technical aspects, along with our ability to organize them will allow us to create a technically correct image an effectively reflect the seen as we see it or want it to appear. Sight and photography are parallels because they are based on the same rules.

Light and Images

Light is a basic element of human life, without it you cannot see. It is a form of energy perceptible to our senses and has the ability to transfer information about its origin and about the bodies which absorb, reflect or transmit a fraction of it. If we make light pass through a converging lens (i.e. a magnifying glass) it's possible to see the light rays cluster together. All rays that originate in the same place converge in a same point on the other side of the lens: this point is an image of its origin. If we consider a scene is made up of infinite points, when a converging lens captures its light we will obtain a complete and detailed image of each one.