Using bokeh as a synonym for background blur, when the word describes the character of that blur rather than the amount.
Editing and retouching
Bokeh
Also called background blur, blurred background or boke. Here is what it means, when it changes what you export, and what people get wrong.
Editing and retouchingRuns on your deviceUpdated 10 August 2026
The short answer
Bokeh is the character of the out-of-focus parts of a photo, not simply how much blur there is. It covers how smoothly the blur falls off, how bright background points render as discs, and whether those discs are round, polygonal, ringed or squashed towards the corners of the frame.
Updated
The short version
Bokeh at a glance
| Quick fact | Detail |
|---|---|
| From | Japanese boke, meaning blur or haze |
| Describes | The quality of blur, not the quantity |
| Disc shape set by | Number and curvature of aperture blades |
| Corner highlights | Often clipped into cat's eye ovals |
| Phone portrait mode | Depth map plus software blur, not optics |
Slide the table sideways to see every column.
Where does the shape of bokeh come from?
An out-of-focus point of light does not stay a point. It spreads into a patch the shape of the lens opening, so the aperture blades draw the background for you. Wide open, the opening is close to a circle and highlights render as round discs. Stop down and the blades intrude, so a seven-bladed lens gives seven-sided highlights unless the blades are curved.
Other lens traits show up in the same patches. Highlights near the edge of the frame get clipped into lens shapes, sometimes called cat's eye, because the barrel itself blocks part of the light path. Concentric rings inside the discs come from the manufacturing of moulded aspherical elements. A bright rim around each disc, which makes foliage look busy and nervous, comes from the way spherical aberration is corrected. None of that is about the amount of blur; it is all about its texture.
Why do phone photos fake it, and how can you tell?
A phone camera has a small sensor and a lens with a very short actual focal length, so almost the whole scene falls inside the depth of field. To get a blurred background it estimates depth (from a second camera, a dedicated depth sensor, or a machine learning model on a single frame), builds a mask of the subject, and blurs everything else by an amount that varies with estimated distance.
The tells are always at the boundary. Loose hair strands vanish or get a soft halo. The arms of glasses blur while the frames stay sharp. Gaps between an arm and a torso stay sharp because the mask treats them as subject. A mug held out in front of a person gets blurred despite being nearer than the face. On products, thin handles, wire, mesh and transparent packaging are where the mask gives up.
Does software blur behave the same as lens blur?
Not by default. A plain Gaussian blur averages neighbouring pixels, so a bright specular point gets diluted by the dark pixels around it and comes out as a dull grey smudge. Optical defocus does the opposite: it spreads that bright point across a disc while keeping its energy, which is why real bokeh glows.
Lens-blur style filters close most of the gap by detecting pixels above a brightness threshold and spreading them across a chosen aperture shape before blurring the rest. If the result looks flat, the highlight handling is usually what is missing rather than the blur radius.
Tools that add blur after the fact, including Photomop's background blur, work from a subject mask rather than from optics, so they inherit the same edge behaviour as phone portrait mode and are best judged by how they handle hair and thin edges.
When is a blurred background worth it for selling?
For profile pictures, team headshots and lifestyle frames, blur separates the subject and hides a room you cannot tidy. For a main marketplace image it is usually the wrong move: platforms generally expect the product sharp on a plain background, and Amazon's product image requirements go further and ask for a pure white background on the main image. A blurred kitchen behind the item reads as a snapshot rather than a listing.
If the background is the problem, replacing it with plain white or cutting the product out gives a cleaner result than blurring it, and it sidesteps the question of whether the blur looks convincing.
What people get wrong about bokeh
Each one is a real failure mode, not a style preference.
Applying a plain Gaussian blur and wondering why the background looks flat, because it dulls bright points instead of spreading them into discs.
Putting a blurred background on a main marketplace image, where a plain sharp background is what platforms and buyers expect.
Judging a portrait mode result at thumbnail size, where hair and glasses errors are invisible until someone opens the full image.
Questions people ask
Bokeh, answered
The follow-up questions people search for once they have the definition.
How do you pronounce bokeh?
Two syllables, roughly BOH-keh, with the second syllable short. It comes from the Japanese word boke, meaning blur or haze. The h was added in English writing to stop people saying it as a single syllable rhyming with poke.
Can you add real bokeh in editing?
You can get close, but not identical. Editing works from a flat image plus an estimated depth map, so it has no information about what sits behind an occluded edge. Lens-blur filters that spread bright highlights into aperture-shaped discs look far more convincing than a plain blur.
Why do the light circles turn into ovals near the corners?
That is mechanical vignetting, often called cat's eye bokeh. Near the edge of the frame, the lens barrel and internal elements block part of the light cone, so the disc gets sliced into a lens shape. Stopping down the aperture reduces it.
Does a wider aperture always give better bokeh?
It gives more blur, which is not the same thing. A wide aperture on a lens with harsh, ring-edged highlights just makes the harshness bigger. Smoothness of falloff and the shape of the highlight discs matter more to how the background reads than the raw amount of defocus.
Same cluster
More from the glossary
Neighbouring entries, so every term in the set is one hop from every other.
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BMP
BMP is Microsoft's raster image format, which stores each pixel's colour value directly with little or no compression.
Chroma subsampling
Chroma subsampling stores colour information at a lower resolution than brightness, because human vision resolves fine detail in brightness far better than in colour.
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