Depth of Field
The range of distance in a scene that appears acceptably sharp. Determined by aperture, focal length, and subject distance - shallow DoF isolates subjects while deep DoF keeps entire scenes in focus.
Depth of field (DoF) is the range of distances from the lens within which objects appear acceptably sharp. Shallow DoF produces background blur isolating the subject, while deep DoF renders entire scenes in focus for landscape and documentary work.
Three factors determine DoF: aperture (f-number), focal length, and subject distance. Wide apertures like f/1.4 produce extremely shallow DoF, while f/16 dramatically increases the in-focus range.
- Circle of confusion (CoC): Maximum blur diameter that appears sharp. For 35mm full-frame,
0.03mmis the conventional standard - Hyperfocal distance: Focus distance where everything from half that distance to infinity is acceptably sharp. Used by landscape photographers to maximize sharpness
- Bokeh quality: Aesthetic character of out-of-focus areas. Lens design (blade count, spherical aberration) produces circular, polygonal, or swirling patterns
- Tilt-shift: Tilting the lens axis changes focal plane orientation, enabling DoF control impossible with conventional lenses (Scheimpflug principle)
Digital processing enables synthetic DoF using depth maps, as in smartphone portrait modes. CG rendering reproduces cinematic DoF through physically-based lens simulations.