Corona Light

This article explains the settings and values for the Corona Light object in Cinema 4D.

Overview

Corona Light is a very flexible type of light that lets you create any light source. It can be set to area light, using either a circle or rectangle; it can be set to be an object, using a sphere, cube, or cylinder.

Object properties

Light Type – This parameter allows you to choose between different light types.

Area – This light type allows you to use different surface shapes to emit light.
Sector – This light type allows you to use a section of an object to emit light in a cone-like shape.
Object – This light type allows you to use different object shapes to emit light.

Light Shape – This parameter allows you to choose between different object shapes to emit light. The available shapes will depend on the selected Light type.

Rectangle – This shape emits light using a rectangular shape.
Circle – This shape emits light using a circular shape.

The Rectangle and Circle light shapes are only available when the Light type is set to Area.

Sphere Sector – This shape emits light using a section of a sphere. This light shape is commonly used to create the light emitted by a spotlight.

The Sphere Sector's light shape is only available when the Light type is set to Sector.

Sphere – This shape emits light using a sphere object.
Cube – This shape emits light using a cube object.
Cylinder – This shape emits light using a cylinder object.

The Sphere, Cube and Cylinder light shapes are only available when the Light type is set to Object.

Size X – This parameter sets the size in the X-axis for the selected light shape.

Size Y – This parameter sets the size in the Y-axis for the selected light shape.

Size Z – This parameter sets the size in the Z-axis for the selected light shape.

The Size Z value is only available when the light shape is set to Cube.

Radius – This parameter sets the radius for the selected light shape.

Angle – This parameter sets the light emitting angle for the selected light shape.

The Angle value is only available when the light shape is set to Sphere Sector.

Length – This parameter sets the length size for the selected light shape.

The Length value is only available when the light shape is set to Cylinder.

Segments – Defines how many segments the geometry of the light has. (min - 3; max - 128) (applies only for Circle, Sphere Sector, Sphere, and Cylinder light shapes).

Directionality – Controls how concentrated the light emission should be around the normal. Higher value creates a spotlight effect.

Bidirectional – When enabled, the lights also emit light on the backside. When disabled, it is black on the backside.

Intensity – This parameter sets the intensity multiplier for the Corona Light.

Units – This parameter sets the units for light emission.

W*sr^-1*m^-2 (Default units) – This is the default option, and it's equal to the 'image' units.
Lumen (lm) – This unit allows you to use real-life lumen values for light emission.
Candela (cd) – This unit allows you to use real-life candela values for light emission.
Lux (lx) – This unit allows you to use real-life lux values for light emission.

Color – This parameter allows selecting specific colors for the light emission.

Temperature – This parameter allows defining the light color using the Kelvin temperature scale.

Visible directly – When enabled, this makes the Corona Light directly visible to the camera.

Visible in reflections – When enabled, this makes the Corona Light directly visible in reflections.

Visible in refractions – When enabled, this makes the Corona Light directly visible in refractions.

Occlude other lights – When enabled, the light blocks shadow rays from other lights in the scene. It is geometry that casts shadows when other lights shine at it.

Shadowcatcher illuminator – Used in combination with shadow catcher materials. If enabled, this light illuminates the shadow catcher instead of casting shadows on it. Enable for CG that are being added to the footage and are not present in the 2D backplate/footage.

Generates caustics – Enabling this option allows for generating caustics.

Visible in editor – When disabled it hides light origin in the viewport.

Prevent black appearance – When enabled, the light continues to emit light in a focused cone or via an IES profile as before, but it appears as non-directional when viewed directly from a camera. This fixes the black appearance of directional light when viewed from an angle, which, although physically correct, may be surprising and unwanted.

IES – Enabling this checkbox allows loading a specific IES light.

Keep sharp pattern (fake) – A fake that modifies the light emission to preserve sharp illumination patterns even with a large area lights. This pattern would otherwise get more blurred with increasing light size.