Digital Camera Photography Technique:
Light & Image VS Vision

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.

Vision and Photography
The sense of sight in a human takes place in the brain as consequence of the interpretation of images formed by the eye. Light rays are captured in the front part (the cornea), pass through the pupil and are projected by the lens (a converging lens) to the back wall of the eye (the retina). The pupil adapts to the intensity of existing light by expanding and contracting. The image formed on the retina is upside down, and is a very detailed replica of the three-dimensional area we have in front of us. The retina is covered with light and color sensitive cells. Variations in the intensity of light and color in the scene projected on the retina generate different nervous stimulations on each point and the information is transmitted to the brain. A photograph is a permanent record of an image. Light from a scene is captured by a converging lens (the camera lens) and projected at a certain instant to a light sensitive surface. The projection of different intensities and colors on a light sensitive surface during the exposure cause a chemical reaction (in case of film) or an electric discharge (in a digital camera) which is proportional to the intensity of the light.

Digital Camera Photography Technique: Light & Image VS Vision

Digital Camera Photography Technique:
Light & Image VS Vision