Bokeh in AI Photos: Shaping Those Blurred Highlights

Bokeh is the aesthetic quality of the out-of-focus parts of a photo: not how much is blurred, but how that blur and the points of light look (Wikipedia). Two photos can have the exact same blurry background and still look completely different: one creamy and calm, the other busy and messy with hard edges around every point of light. In an AI generator you don't set a real lens, but the models are trained on photos with that look, so you steer it with the right words. Below you'll read what shapes your highlights and how to name good bokeh in your prompt.

Bokeh and depth of field are not the same

Depth of field is about how much of your image is sharp; bokeh is about how the out-of-focus part looks. You can have a shallow depth of field with ugly, hard bokeh, or with soft, creamy bokeh. One dial sets the amount of blur, the other sets its flavour.

For an AI photo, that means you name two things separately: how much is blurred (shallow depth of field, blurred background) and how that blur looks (creamy bokeh, soft round bokeh). Ask only for a blurred background and the model picks the bokeh itself, which doesn't always turn out well.

What shapes your highlights?

The shape of an out-of-focus point of light comes from the lens opening. In a real camera the aperture blades form that opening, and a blurred highlight takes its shape: six straight blades make hexagonal highlights, while lenses with more or curved blades give a round shape (Wikipedia).

More blades means rounder bokeh. Wikipedia notes that a 9-bladed 85mm lens at f/1.8 already produces great bokeh, and that lenses with 11, 12 or 15 blades excel in bokeh quality. In an AI generator you don't set blades, but words do the work: round bokeh and creamy bokeh call up the soft, round look, while hexagonal bokeh gives the angular shape. If you get polygons by accident, add round, soft bokeh explicitly.

What makes bokeh bigger and softer?

You get bigger, softer highlights by stacking four things: a wide aperture (small f-number, such as f/1.4 to f/2.8), a longer lens (85mm or more), a subject close to the camera, and a background clearly far behind your subject. All four enlarge the out-of-focus circles.

In your prompt you combine them: 85mm, f/1.4, shallow depth of field, plus a scene where the background sits at a distance, for example a street or park behind the subject. Without that distance to the background there's little left to blur, however small your f-number is.

Special bokeh looks (and what to call them)

Beyond clean round bokeh there are recognisable, characterful variants. They come from specific lenses, and most models know the terms:

• Swirly bokeh: the background seems to swirl toward the corners, a look from vintage lenses like the Helios 58mm. Prompt: swirly bokeh.
• Cat's-eye: toward the frame edge, round highlights squeeze into oval cat's eyes because of vignetting. Prompt: cat's eye bokeh.
• Doughnut or ring: a mirror lens blocks the centre of the opening, turning highlights into rings (Wikipedia). Prompt: donut bokeh or mirror lens bokeh.
• Anamorphic oval: anamorphic (cinema) lenses stretch highlights into ovals (Wikipedia). Prompt: anamorphic bokeh or oval bokeh.
• Soap bubble: bubbles with a sharp outlined rim instead of a soft edge. Prompt: soap bubble bokeh.

Use these on purpose: they add character, but a busy swirling background distracts faster than a calm, creamy one.

How to steer bokeh in your prompt

Name the effect with fixed English terms and let the model do the rest. A few useful building blocks:

• Calm and creamy: creamy bokeh, soft round bokeh, smooth blurred background, no harsh outlines.
• Visible bokeh balls: glowing bokeh balls, plus a real light source behind your subject, such as fairy lights, streetlights or sunlight through leaves.
• Characterful: swirly bokeh, anamorphic bokeh, cat's eye bokeh.

Example: "portrait of a woman on a city street at night, 85mm, f/1.4, shallow depth of field, creamy round bokeh, glowing streetlight bokeh balls in the background". Not sure how to phrase it? A prompt generator turns your idea into a clean description, lens and bokeh included, which you then use in the photo generator.

Bokeh in AI video

In video bokeh works the same way, only moving: light balls behind a walking subject slide and shift along, which instantly makes a scene feel cinematic. In the video generator, describe the bokeh and depth of field first and the camera movement after, so the model knows what should stay blurred. Keep the bokeh style consistent per scene, just like your light and colour, or the background jumps from shot to shot.

Common mistakes

• Asking for bokeh without a light source. Those round balls only appear when small, bright points sit behind your subject. A flat wall gives no bokeh balls.
• Too busy a background. Dozens of bright points distract. Ask for fewer, softer lights or a calmer background.
• Typing only "blurred background". Then the model picks the bokeh itself. Name the look separately with creamy or round bokeh.
• Bokeh that changes across a series. Building a series with the same persona? Keep the same bokeh terms, just like face and clothing.

Frequently asked questions

What is the difference between bokeh and depth of field?

Depth of field is how much of your image is sharp. Bokeh is how the out-of-focus parts look: soft and round, or hard and messy. You can have the same amount of blur with beautiful or with ugly bokeh.

Why are my highlights angular instead of round?

Then the model is imitating a lens with straight aperture blades, which gives polygonal highlights. Add round, soft, creamy bokeh to your prompt to force round shapes.

How do I get those round light balls in the background?

Place small light sources behind your subject, such as fairy lights, streetlights or sun through leaves, and keep them out of focus. Name them in your prompt and add glowing bokeh balls.

Bokeh is one of the fastest ways to make a photo look more expensive and cinematic: one line in your prompt decides whether your background falls away calmly or distracts. Create an account and render the same scene once with creamy round bokeh and once with swirly bokeh in the photo generator. You'll see straight away which look makes your subject stand out best.