The Glow effect finds the brighter parts of an image and then brightens those and surrounding pixels to create a diffuse, glowing aura. The Glow effect can also simulate overexposure of brightly lit objects. You can base the glow on either the original colors of the image or on its alpha channel. Glows based on alpha channels produce diffuse brightness only at the edges of the image, between the opaque and transparent regions. You can also use the Glow effect to create a gradient glow between two colors (A and B colors) and to create multicolor effects with looping.

Rendering the Glow effect at Best quality can change the appearance of the layer. This change is especially true if you use Adobe Photoshop arbitrary maps to color the glows. Be sure to preview at Best quality before you render the effect.

Glows tend to be brighter and more realistic in 32-bpc projects. Consider working in 32-bpc color for this reason, even if footage items don’t contain high–dynamic range color values.

This effect works with 8-bpc, 16-bpc, and 32-bpc color.

Original (left), and with effect applied (right)

Glow Based On

Determines whether glow is based on color values or transparency values.

Glow Threshold

Sets a threshold as a percentage brightness to which the glow isn’t applied. A lower percentage produces more glow; a higher percentage produces less.

Glow Radius

The distance, in pixels, that the glow extends out from the bright areas of the image. Larger values produce diffuse glows; smaller values produce glows with sharp edges.

Glow Intensity

The brightness of the glow.

Composite Original

Specifies how to composite the effect results with the layer. On Top places the glow on top of the image, using the blending method selected for Glow Operation. Behind places the glow behind the image, creating a backlighting result. None separates the glow from the image.

To reduce the layer to the glow only, choose None for Composite Original and None for Glow Operation. To achieve a glow effect for text that knocks out (blocks) all layers below it, choose Silhouette Alpha for Glow Operation. These glow effects are more noticeable if the image has a feathered edge.

Glow Colors

The colors of the glow. A & B Colors creates a gradient glow using the colors specified by Color A and Color B controls.

Color Looping

The shape of the gradient curve to use if A & B Colors is selected for Glow Colors.

Color Loops

Creates multicolor ringing in the glow, if you select two or more loops. A single loop cycles through the gradient (or arbitrary map) specified for Glow Colors.

Color Phase

Where in the color cycle to begin color loops. By default, color loops begin at the origin of the first loop.

A & B Midpoint

The midpoint specifies the balance between the two colors used in the gradient. Lower percentages use less of the A color. Higher percentages use less of the B color.

Color A, Color B

The color of the glow if you choose A & B Colors for Glow Colors.

Glow Dimensions

Specifies whether the glow is horizontal, vertical, or both.