gen-define-aperture-and-depth-of-field-and-give-one-short-worked-609a

Define aperture and depth of field and give one short worked example.

# Aperture and Depth of Field ## Aperture The opening in a lens through which light passes, measured in f-stops (f/1.4, f/2.8, f/5.6, etc.). A **lower f-number** = larger opening = more light. A **higher f-number** = smaller opening = less light. ## Depth of Field (DOF) The zone of acceptable sharpness in a photo, from the nearest to farthest objects that appear in focus. - **Shallow DOF**: Small zone of focus (blurry background) - **Deep DOF**: Large zone of focus (most of scene sharp) ### Key relationship: - **Large aperture** (small f-number like f/1.8) → **Shallow DOF** - **Small aperture** (large f-number like f/16) → **Deep DOF** ## Worked Example **Scenario**: Portrait photography - **Settings**: 50mm lens, f/1.8, subject 6 feet away - **Result**: Only the subject's face is sharp; the background 20 feet behind blurs into soft bokeh (shallow DOF) **Alternative**: Same scene at f/11 - **Result**: Both the subject AND background trees are noticeably sharper (deep DOF) **Why?** At f/1.8, the wide aperture creates a razor-thin plane of focus. At f/11, the smaller opening increases the range of acceptable sharpness.