Blur Background

Vignette Blur, Not Portrait Mode

A phone's portrait mode builds a depth map from two lenses or a neural network and blurs by distance. This tool doesn't do any of that. It blurs everything outside a circle or a rectangle that you position yourself, so what you get is a vignette (or, with a wide flat rectangle, a tilt-shift). Used on purpose, the effect looks good. Used as a stand-in for depth of field it looks wrong, because anything at the same distance as your subject still goes soft if it falls outside the shape.

How the composite is assembled

The picture is drawn twice, once through a blur filter and once sharp. A gradient mask keeps the sharp copy only inside your focus shape, and the two layers are stacked. None of these steps looks at what's actually in the photo.

The radius is a real measurement

Blur radius is set in pixels of the exported image. The on-screen preview scales the radius by the same factor it scales the picture, so what you see is what you download. A 12 px radius that looks strong on a 900 px web image is barely noticeable on a 6,000 px original, so pick the radius with the final published size in mind.

Feathering, which now works

Feathering controls how gradually the sharp region fades into the blur. At zero you get a visible ring around the sharp area, and anyone looking will spot the edit. Push it toward the top of its range and the transition spreads across a large part of the frame, so the blur reads as atmosphere and stops looking like an effect.

This control was broken until recently. The value was read in the wrong units and changed nothing on the canvas, so if you tried it before and decided it was decorative, give it another go.

Placing the focus

Tap or click anywhere on the preview to move the centre point. There are also two percentage boxes for exact values, which you'll want when a set of images needs the focus in the same place. The focus size slider sets how big the shape is: for a circle it's a proportion of the shorter edge, and for a rectangle it scales both sides of the frame together.

When the effect gives itself away

Two things give it away. One is a subject that extends past the focus shape, so an arm or a shoulder goes soft halfway along its length. The other is a background object that stays sharp because it happens to sit inside the circle, while everything else at its distance is blurred. Either way, the fix is to move the shape, widen it, or settle for a gentler radius.

It works well for hiding a messy room behind a product, or calming a busy street behind a portrait taken from far enough away. It's also handy for pulling the eye toward one panel of a documentation screenshot.

Blur isn't redaction

Don't use this to hide a face, a licence plate or an address. The region is picked by geometry, with no regard for what's in it, and the strength is just a slider with no guarantee behind it. A blur that looks impenetrable at preview size can still leave recoverable structure. When something must not be in the picture, cut it out of the frame with Crop Image instead, and check what the file says about itself with Image Metadata Viewer before you send it anywhere.