Depth of Field

Definition

Depth of Field (DoF) refers to the range of distance in front of the camera within which objects are perceived as sufficiently sharp. Outside this range, sharpness gradually decreases, creating the characteristic "bokeh" effect.

Influencing Factors

Depth of field is determined by four main factors:

1. Aperture

Mnemonic: Wide aperture = shallow depth of field

2. Focal Length

• Telephoto (85mm+): Shallower depth of field
• Normal (35-50mm): Medium depth of field
• Wide-angle (<35mm): Deeper depth of field

3. Subject Distance

• Close: Shallow depth of field
• Far: Deeper depth of field

4. Sensor Size

• Full Frame: Shallower depth of field
• Super 35: Medium depth of field
• MFT: Deeper depth of field

Depth of Field Formula (Simplified)

Greater depth of field achieved by:
• Smaller aperture (higher f-number)
• Shorter focal length
• Greater subject distance
• Smaller sensor

Shallower depth of field achieved by:
• Wide aperture (low f-number)
• Longer focal length
• Shorter subject distance
• Larger sensor

Creative Application

Shallow Depth of Field (Shallow Focus)

Effect:

• Isolation of the main subject
• Intimate, emotional atmosphere
• Guiding the viewer's eye
• "Cinematic" look

Application:

• Portraits, close-ups
• Emotional scenes
• Visual storytelling

Deep Depth of Field (Deep Focus)

Effect:

• Contextualization
• Democratic image (everything is equally important)
• Documentary character
• Epic scope

Application:

• Establishing shots
• Scenes with important foreground and background elements
• Staging in depth

Depth of Field Scale

SHALLOW ←――――――――――――――――――→ DEEP

Portrait with Interview Landscape
85mm f/1.4 50mm f/4 24mm f/11

Isolation Balance Context
Emotion Neutrality Information

Practical Calculation

Hyperfocal Distance

The point at which, with a given aperture, everything from that point to infinity is in focus:

Hyperfocal Distance ≈ f² / (N × c)

f = Focal length
N = Aperture number
c = Circle of confusion (approx. 0.03mm for full frame)

Depth of Field Calculator

For precise calculations: Apps like "DoF Calculator" or "Artemis"

Typical Setups

Creative Techniques

Split Diopter

Divides the image into two planes of focus – famously used by Brian De Palma.

Rack Focus

Shifts the focus from one subject to another.

Deep Focus Staging

Staging across multiple planes of focus (Orson Welles, William Wyler).

Cinematic Applications

Shallow Focus

Classic Cinematography:

• Portrait Mode: 85mm f/1.4-f/2.0 at 3 meters distance = ~5cm depth of field
• Psychological effect: Isolation, vulnerability, emotional intimacy
• Examples: "Powaqqatsi" (1988) DP Vittorio Storaro, "Her" (2013) DP Hoyte van Hoytema

Deep Focus

Classic Examples:

• "Citizen Kane" (1941): f/8-f/11 with 28mm wide-angle creates focus across multiple planes
• "The Shining" (1980): Steadicam corridor sequences with f/5.6-f/8 for continuous focus
• "Master and Commander" (2003): Ship deck scenes with f/5.6 for deep focus

Focus Tracking with Movement

Technical Challenge:
The focus puller must continuously adjust the distance as the actor moves.

Example: 85mm f/2.8 at 3-6 meters distance

• Acceptable depth of field: 15cm (±7.5cm around the focus point)
• If the actor moves 10cm closer: Focus becomes soft
• Solution: Focus marks on the floor, electronic focus controls (Cmotion, Easyrig)

See also

• Aperture
• Bokeh
• Shallow Focus
• Deep Focus
• Rack Focus