Using Diamond Gradients for Starburst Effects

The diamond gradient is one of the most effective tools in image editing for generating realistic glints, lens flares, and dynamic starbursts. By manipulating the geometric properties of a four-point gradient, stretching the falloff, and layering multiple transformed copies, you can create custom light effects to accentuate jewelry, highlights, or nighttime light sources. This guide walks you through the step-by-step process of setting up, shaping, and blending a diamond gradient into a convincing starburst.

Setting Up the Canvas and Gradient Tool

To achieve the best visibility and control, build the starburst on its own transparent layer over a dark background.

  1. Create a new layer above your working image and name it "Starburst Core."
  2. Select the Gradient Tool in your editing software (such as Photoshop, GIMP, or Photopea).
  3. In the gradient options bar, choose the Diamond Gradient style.
  4. Set the gradient colors to run from pure white at the center to transparent black (or completely transparent white) at the edge. A smooth transition from opaque center to transparent periphery creates the light falloff essential for a glow.

Generating the Primary Rays

The standard diamond gradient produces a soft, square-like diamond shape. Transforming this shape creates the sharp, needle-like rays of a starburst.

  1. Click on the center point where you want the light burst to originate, then drag outward a short distance and release.
  2. Open the Free Transform tool (Ctrl+T or Cmd+T).
  3. Constrain your transform to pull the horizontal edges inward while stretching the vertical dimension, or pull the vertical edges inward while stretching the horizontal width. This flattens the diamond into a sharp, narrow light spike with soft, faded tips.
  4. Duplicate the transformed layer.
  5. Rotate the duplicate layer 90 degrees to create the intersecting perpendicular ray, forming a classic four-point star.

Expanding to Multi-Point Starbursts

Real-world optical starbursts—such as those created by small camera apertures—often display six, eight, or more light spikes.

  1. Merge or group your horizontal and vertical ray layers.
  2. Duplicate this primary four-point star group.
  3. Use the transform tool to scale the duplicate down to roughly 50% to 70% of the original size.
  4. Rotate the scaled copy by 45 degrees. The shorter diagonal rays add depth and realism, mimicking natural lens diffraction.
  5. If you want a more complex flare, repeat the process with a smaller scale and a 22.5-degree rotation, keeping the secondary rays lower in opacity.

Blending and Adding Core Glow

A convincing starburst requires intense center brightness and seamless integration into the scene.

  1. Create a new layer beneath your ray layers.
  2. Use a soft, round brush or a standard radial gradient with pure white to add a small circular glow directly behind the center of the rays.
  3. Select all the starburst layers (the rays and the center glow) and set their layer blend mode to Screen, Linear Dodge (Add), or Color Dodge. This causes the light values to interact naturally with the colors beneath them.
  4. To add color, apply a Hue/Saturation adjustment layer clipped to the starburst, or create an Outer Glow layer style using a warm gold, cool blue, or the ambient color of your scene.
  5. Lower the master opacity of the starburst group until it blends harmoniously with the image without blowing out surrounding details.