Photography 101: Aperture and Depth of FieldBy James P Knell

Introduction• As the chairman of the SIMA umbrella of companies,

James P. Knell plays an integral role in the management of the SIMA Management Corporation and the SIMA Corporation. Outside of his work with SIMA, James P. Knell is an avid photographer.

In the world of photography, aperture represents one of the most important aspects of a photograph. Defined simply as the size of the opening in the lens, aperture has a major impact on the depth of field in a photograph.

Aperture and Depth of Field• As a general rule, small apertures produce a large

depth of field, meaning that the majority of an image will be in focus. Conversely, a large aperture will result in a photograph with only close objects in focus. Photographers can manipulate this phenomenon in an almost infinite number of ways. Landscape photographers typically prefer to capture as much of a scene as possible with small apertures, while portrait photographers often use large apertures to place the focus on their subjects instead of the background.