New in Carbon (Drop 2)
Please note in Carbon (Drop 4) the Value Blend settings are now found within a tab in the Content section, reducing the need to scroll the light properties panel which was getting quite tall.
Value Blend is a new section added to the Light Properties panel. It allows blending of the luminosity values from a secondary piece of content with the primary light content. It provides a way to tweak the character of the light source. For example adding a hot spot into an existing soft box, or graduating the light brightness across your light.
Content types for Value Blend are: Image, Gradient, Flat and the new Box Gradient
Blend Modes for Value Blend are: Add, Multiply, Over, Low Pass and Amplify
Here are some effects you can create: Value Blend Off - showing original content for reference
Value Blend - Gradient used with Multiply blend mode, to darken areas of the light using a radial gradient, top cornerYou can see how the character of the light changes in the reflections on the render view. It's less flat and more dynamic.
Value Blend - Gradient used with Multiply blend mode, to darken areas of the light using a radial gradient, bottom corner
Value Blend - Gradient used with Multiply blend mode, to darken areas of the light using a radial gradient, centered
Value Blend - Gradient used with Multiply blend mode, to darken areas of the light using a linear gradient, top edge
Value Blend - Image used with Multiply blend mode to change brightness of a soft box
Value Blend - Flat used with Low Pass blend mode, this is clamping the values of the spot light on the right, the character of the light is maintained, but the hot spot of the light bulb is removed