Blender Sun Light Angle Property Explained

In Blender, the Light Angle property on a Sun Light controls the angular diameter of the light source in the sky, which directly dictates the sharpness or softness of the shadows it casts. While a Sun Light emits parallel rays across the entire scene regardless of its position, adjusting the Angle setting allows you to simulate the apparent size of the sun, creating realistic shadow diffusion and penumbra effects in both Cycles and EEVEE.

How the Angle Affects Shadows

The Angle property is measured in degrees and defines how spread out the incoming light rays are relative to each other:

  • 0.00° (Hard Shadows): A value of zero treats the sun as an infinitely small point source in the sky. All light rays are perfectly parallel, resulting in razor-sharp, hard-edged shadows across all distances.
  • Default Value (0.526°): Blender's default angle represents the actual physical angular diameter of the Sun as seen from Earth. This produces realistic, slightly softened shadow edges that naturally blur more as the distance between the caster and receiver increases.
  • Higher Angles (Soft Shadows): Increasing the angle to values such as 5° to 20° simulates a larger light source, such as the sun behind thin clouds, haze, or stylized lighting. This creates wide penumbras with significantly blurred shadow boundaries.

Key Characteristics and Behavior

  • Light Intensity Remains Constant: Changing the Angle property only changes how diffuse the shadow borders are; it does not change the total brightness or energy output of the Sun Light.
  • Contact Hardening: Because the property physically simulates light coming from a disk rather than a point, shadows remain sharp near the contact point of an object and gradually soften as the shadow stretches further away.
  • Render Engines: In Cycles, the angle directly affects ray-traced shadow softness. In EEVEE, the "Soft Shadows" option must typically be enabled in the render properties to accurately display the shadow gradient created by the Angle property.