Monday, April 27, 2009

Varying Shutter Speed and Aperture with Point-And-Shoot Cameras

Point-And-Shoot cameras have democratized photography. Having a camera that is low cost, easy to carry in almost any situation and allows the user to ignore all technical variables results in a camera where one can concentrate on framing, where to stand and the quality of the light. This is a wonderful way to make photographs. Technical variables should be secondary to composition, but by limiting one's technical options compositional options are also limited sometimes. Although it is not possible to turn a point-and-shoot camera into an SLR thru clever workarounds, these cameras technical options can be stretched a bit by working with ISO changes.

By varying the ISO the camera changes the shutter speed and aperture for any given situation. Changes in shutter speed make motion look different at different speeds. This is most evident when the motion is going across the frame. By taking several photographs one can watch how motion is rendered on the monitor giving the camera operator a little bit of ability to control how motion is rendered. It is not even closely equivalent to the options to vary how motion is rendered with an SLR, but it's better than nothing.

Changes of aperture can be obtained the same way, but the results are much less significant. The shorter the lens the less significant the change of aperture. The closer the camera operator is to the subject the more changes in aperture become noticeable with any lens. Point-And-Shoot cameras have very short lenses making it very difficult show variations from changing the aperture under any set of conditions.

Lastly – It is important to not loose sight of what the ISO control’s intended use is. It is for reconfiguring the camera controls to handle various lighting conditions. Typically in a sunny, open outdoor setting one might use an ISO of 50 or 100 and indoors use an ISO of 400. If on auto ISO, the camera would make similar choices. The larger the ISO number the greater the chance of the photograph having large areas of colored speckles. The technical term for this is noise. Also the larger the ISO number the softer the colors are and texture starts to fall off.

©2009 Paul Light all rights reserved


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