Exposure Basics

Exposure in the context of photography is the amount of light which the photographic film (or the sensor in a digital camera) is exposed to . If that sounds simple then read on. Exposure is one of the central concepts of photography. The art of photography rests on the perfection in exposure. Optimum exposure is the one in which just the right amount of light is let in through the aperture to render the fineness in the texture, the color tones and overall brightness in one image.

Optimal Exposure - f/4.2, 1/60s, ISO 200, 180-200@35mm

• Overexposure: When more than optimal light is allowed on to the film, the result are overly bright and almost washed out by the light. It’s almost as if the camera has been blinded by the sun. Overexposure result in the loss of texture and detail in the final image. The colors are also washed out to a large extent.
  

  Overexposure - f/4.2, 1/15s, ISO 200, 18-200@35mm

• Underexposure: Less then optimal light on the film results in underexposure. The overall scene is poorly illuminated. As in an overexposed image, a loss of texture and detail is evident. Colors may be saturated beyond the original. Underexposure is generally caused by a high shutter speed, low light or small aperture.
  

  Underexposure - f/4.2, 1/250s, ISO 200, 18-200@35mm

Next we will see how various metering modes work to provide the exposure best suited to the situation. Also we will see how you can manually control the exposure for various situations.