BetterPhoto Q&A
Category: Available Light in Photography

LIGHT

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July 02, 2003

Sounds are a form of radiated energy made by vibrating air. Sounds can be recorded by using a microphone that can detect these vibrations and a tape recorder with tape in it. After recording the sounds, the tape can be played back at a different time and in a different place for others to hear.

The photographic process is the same type of thing, except instead of sounds, it works with light. Light is radiated electro-magnetic energy with both wave and particle properties (photons). Film, or some other device such as the CCD in a digital camera detects light. Film also records it; film chemically changes when exposed to light. In a digital, the electronics around the CCD records it and it is stored in memory. When the shutter opens, the recording begins. When the shutter closes, it ends. After you process the film or download the digital file, you "play back" the light recording for others to see at a different time and place. A photograph is nothing **but** a recording of light made for the time the shutter on the camera was open. Thus, the photograph is not the subject itself, otherwise you would have a "clone" of it to carry around. It's a recording of the light reflected (or emitted) by the subject. Light is the ONLY thing that passes through the lens to the film (or CCD in a digital). Without light, there is NO photograph.

In making a photograph, light travels the following path:
Light Source -> Subject -> Lens -> Film (or CCD)
If any one of these things changes, the light being recorded when the shutter is opened will be different and the resulting photograph will be different.

Photography = Making Recordings of Light
Photograph = A Light Recording

-- John

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July 02, 2003