The Light Analysis Render Element provides visual representation of the lighting intensity in the rendered frame. It maps Illuminance and Luminance information as color gradient or a grid of measured values onto the frame. The Illuminance and Luminance channels are internally created during rendering. Once rendered, the parameters can be adjusted and the analysis can be updated without the need to re-render.
The VRayLightingAnalysis render element is a post-effect and is only updated once the rendering is complete. During the render, the VRayLightingAnalysis may display some approximation to the false-color image, but it should not be interpreted as being the final result.