The art of compositing consists in merging two or more images making them look like they have been shot at the same time with the same camera and lenses, under the same lighting conditions. Applying the physics of light in a photorealistic environment could not always be synthesised in simple formulas or fixed structures due to the complexity of the light phenomena but understanding the journey a ray of light has taken from its source to get to your screen could lead to a more scientific analysis of the image merge process to replicate and emulate the qualities and artefacts of light. In order to log the events in the lifetime of a specific ray of light Victor Perez proposes a Mind Mapping Analysis Structure to translate the physics of light into mathematical operations within Foundry® NUKE’s nodal-based compositor. An articulated system of observation to guide compositing artists in the fantastic odyssey into the invisible.