Video April 13, 2026 4 min read

DOF in Video: How It Differs from Photography

The physics of depth of field is the same in video and photography. How you manage it is not. Shutter speed is locked, stopping down costs you exposure you cannot easily get back, and a focus miss ruins seconds of footage rather than one frame.

The shutter speed is not free

In photography, aperture and shutter speed are independent. In video, the shutter speed sets how motion looks. The 180-degree rule says to use about twice the frame rate: 1/50 s at 24 fps, 1/60 s at 30 fps, 1/125 s at 60 fps, 1/250 s at 120 fps. Go much faster and motion looks stuttery, much slower and it smears. So you cannot compensate for an aperture change with the shutter. If you stop down from f/1.8 to f/8 for more depth, you lose about four and a half stops, and ISO and neutral density filters are the only levers left.

ND filters

In full sun at ISO 100, a 1/50 s shutter needs about f/22 for correct exposure, since sunny 16 gives f/16 at 1/100 s. To shoot at f/2.8 you must remove about six stops, and at f/1.4 about eight. Cameras with a higher base ISO need more: at ISO 800 add three stops. That is what ND filters do.

Full sun, 1/50 s	ISO 100	ISO 800
f/5.6	4 stops	7 stops
f/2.8	6 stops	9 stops
f/1.4	8 stops	11 stops

ND4 removes 2 stops, ND8 3, ND64 6, ND256 8 and ND1000 10. A variable ND is the practical choice for run-and-gun work, because you can adjust as the light changes, though some variable filters show a dark cross pattern at their extremes. Fixed filters are optically cleaner but you need several.

Shallow focus and its risks

A subject sharp against a creamy background became the signature look of large-sensor video, and it still works. But a miss costs the length of the shot. At f/1.8 with a subject moving even slightly toward or away from the camera, autofocus has to track a zone measured in centimetres. For scale, on full frame an 85 mm f/1.8 at 2 m has a zone of about 6 cm, while a 50 mm at f/2.8 from 2.5 m has about 40 cm. The video focus distance guide on our other site goes through how much margin you need.

Shallow focus works when the subject is stationary or moving sideways, in controlled settings such as interviews, on a stable support, with a consistent distance and reliable face tracking. It fails with a subject walking toward or away from you, a handheld camera moving freely, several subjects at different distances, or a head turning so that near and far eyes swap planes. Most experienced shooters settle on f/2.8 to f/4 for video: enough separation to look cinematic, enough depth to forgive small movements.

Focus pulls

Racking focus from one subject to another has no equivalent in photography. Cinema uses a dedicated focus puller with a follow-focus unit and distance marks on the lens. Solo shooters can use autofocus on recent mirrorless cameras, though a skilled manual pull is smoother. Many cameras let you set the speed of the focus transition. The default is often too fast, so a slower setting looks more deliberate. Focus breathing, where the field of view changes as you rack, is a lens property. Some cameras compensate for it with certain lenses.

Sensor crop in video

The sensor size relationships are the same as for stills, with one catch: many cameras crop the sensor in video modes, which changes both the field of view and the depth of field.

Mode	Effective sensor	Depth of field vs full frame
Full frame, uncropped	Full frame	Same
Full frame with a 1.5x crop	About APS-C	About 1.2 stops deeper
APS-C, uncropped	APS-C	About 1.2 stops deeper
Super 35 cinema	Roughly APS-C	About 1.2 stops deeper
Micro Four Thirds	Micro Four Thirds	About 2 stops deeper

With a 1.5x crop, your 50 mm lens frames like a 75 mm. Check the crop for each resolution and frame rate on your camera, since it often differs between modes.

Rolling shutter

Video is always read out electronically, so rolling shutter, the skew on fast pans and moving subjects, is a property of the sensor readout, not of your aperture choice. It does not offer a way around ND filters, and fast-readout sensors reduce it.

Aperture by scenario

Scenario	Aperture
Interview, stationary	f/2 to f/2.8
Documentary, walking subject	f/4 to f/5.6
Scripted, controlled	f/1.8 to f/2.8, with a focus puller or exact blocking
Event or wedding	f/2.8 to f/4
Product or tabletop	f/2.8 to f/5.6
Landscape or establishing shot	f/8 to f/11, with ND
Handheld run-and-gun	f/4 to f/5.6

The cinematic look is more than blur

Shallow focus became linked with cinema because cinema cameras have large sensors and shoot 24 fps with a 1/50 s shutter. Frame rate, motion blur, grading and lens character count as much. Software background blur on phones has improved, but it can still show edge errors, as the post on portrait mode versus real bokeh explains. Optical blur responds naturally as the subject moves, and managing that is what controlling video depth of field is about.

To check the zone for any lens and distance, use the calculator.