The factors discussed in the following sections govern the depth of field in a photograph.
Aperture This part of the photographic process is affected more by the practical decisions you make than by artistic ones. Depth of field can be strictly
anaged by tangible changes m in aperture size or f-stops. As alluded to earlier in the discussion of lenses, large f-stop numbers—ƒ/22, ƒ/16, or ƒ/11—correspond with smaller apertures that produce the widest depth of field. Small f-stop numbers—ƒ/2, ƒ/2.8, or ƒ/4—correspond with larger apertures producing
limited depth of field. Ascending through the f-stops from ƒ/2.8 to ƒ/4 to ƒ/5.6 and so on, depth of field expands in your image with each subsequent click to the next smaller aperture. When you reach ƒ/22, you’ve attained maximum aperture depth of field, depending on the other factors mentioned later.
A 300mm lens at ƒ/7 with a focus point midway into the scene produced this image with only limited depth of field. Flowers in the center of the composition are in sharp focus, while flowers in the foreground and background are out of focus.
Viewpoint and Perspective
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