Depth of Field in Games: Blur, Cost and When to Turn It Off
Depth of field (DoF) is a post-processing effect that blurs objects in front of or behind a chosen focus point, the way a camera lens does. Game engines use it to draw your eye to one thing and to give the image a photographic look.
Unreal Engine's documentation describes it in those terms: a blur that depends on distance from the focal point, used to point attention at a subject and to make a render look more like a photograph or film. Unreal offers two versions: Cinematic depth of field for desktop and console, with camera-style controls, and a lower-cost Mobile depth of field for phones.
Where games use it
- Cutscenes and scripted moments. Nobody controls the camera, so focus can be set by the director. This use needs no player input.
- Aiming down sights. Blurring the background so the target stands out. Titanfall 2 had an "ADS Depth of Field" option under Options, Video, HUD Options.
- Social spaces. Destiny 2's guide says its blur is applied in cinematics, scripted moments, third-person social spaces and when aiming down sights.
What it costs
NVIDIA's graphics guides tested DoF on launch-era hardware (GTA V guide 21 April 2015, Titanfall 2 guide 2016, Destiny 2 guide 17 October 2017). The numbers are small and old, but they show the pattern: the cheap blur is almost free, and the cinematic bokeh version is not.
| Game | Result in NVIDIA's guide |
|---|---|
| Destiny 2 | Low uses a basic low-cost blur filter; High uses a cinematic bokeh effect at half the sample count in gameplay, Highest doubles the samples. Highest lowered frame rate by about 6 FPS, High by 2.2 FPS |
| Grand Theft Auto V | At most 1.6 FPS lost in gameplay, a few more in cutscenes. Available when PostFX is Very High or Ultra |
| Titanfall 2 | Turning off ADS depth of field gave a little over 1 FPS |
The guides date from the games' PC launches, so treat the figures as a sense of scale, not as a prediction for your hardware.
Why many players switch it off
- It hides background detail. Titanfall 2's guide tells players who want to see the background while aiming to disable the ADS option, and a sharp image is what competitive players usually want.
- It can fail. The GTA V guide notes that it can occasionally blur the whole screen during gameplay and then snap back sharply.
- It is a matter of taste. The same guide calls it a personal preference setting, like motion blur.
Depth of field vs similar settings
| Effect | What it changes |
|---|---|
| Depth of field | Blur by distance from the focus point |
| Motion blur | Smears the picture when the camera or objects move |
| Vignette | Darkens the screen edges, see the vignette page |
| Render scale | Changes the internal resolution, see render scale |
Tips
- If you play a shooter for results, try it off for a week and compare. For cutscene-heavy single-player games it is a matter of look.
- If the game gives Low, High and Highest, check what each level does. In Destiny 2, Low is the basic filter and the upper two add bokeh.
- Look for it under Post-Processing, Effects or HUD options, not under resolution.
Related terms
- Vignette: another lens effect applied to the whole image.
- Render scale: the setting that actually changes sharpness and cost most.
- Graphics settings glossary: bloom, volumetric fog and other post-processing options.
- Reticle: the aiming point that DoF often keeps in focus.
- General gaming terms: other graphics-settings terms that apply to any game.
FAQ
Does depth of field increase FPS when turned off?
A little. NVIDIA measured about 6 FPS for Destiny 2's Highest setting on launch-era hardware and about 1 FPS for Titanfall 2's ADS option.
Is depth of field good for competitive games?
Many shooter players turn it off because it blurs the background, where enemies can appear.
What is the difference between depth of field and motion blur?
Depth of field blurs by distance from a focus point. Motion blur smears the image when things move.
Why is there bokeh in some settings?
Bokeh is the shape of out-of-focus highlights. Destiny 2's High and Highest depth of field simulate it and cost more than the basic Low blur.
