A SHORT GUIDE TO PHOTOGRAPHY
Photography can be a rewarding pursuit. It is a broad and disciplined field that can take years to master. But the pleasure in making photographs and the joy of capturing a magical moment cannot be compared. The guide is an introduction to some basic pho- tographic principles.
The lens aperture controls not only exposure, but also depth of field; the area between the closest object in focus and the furthest object in focus. The larger the aperture value, the greater the depth of field and the longer the shutter speed needed to make the exposure. The smaller the aperture value, the shallower the depth of field and the faster the shutter speed needed to make the exposure. Usually landscape photographs use a large depth of field (large
aperture value) to keep the fore- ground and background in focus, and portraits use a shallow depth of field (small aperture value) to separate the subject from the background.
Depth of field also changes with focal length. The smaller the focal length, the greater the depth of field; the longer the focal length, the shallower the depth of field.
The shutter controls not only exposure, but also the ability to stop motion. Fast shutter speeds are used in sport pho- tography to stop action. Slow shutter speeds can be used to show the flow of motion such as water cascading over a waterfall. The use of a tripod is recom- mended with slow shutter speeds.
The change in aperture and shutter speed is not apparent in the live image. Unlike film cameras, test photographs can be taken and immediately viewed. For critical work, take a test photograph at the set aperture or shutter speed and view the result in quick view (p.34). The image can be deleted if not acceptable and another test image can be taken at a different setting.
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