Reflectance Transformation Imaging (RTI) is an advanced photographic technique used to create a digital torch to light the surface of the photographic subject with raking light. This exposes the finest detail of the surface topography. Combined with image processing tools within the software, RTI can be used to analyse very low topography detail such as fossil imprints in bedding layers (British Geological Survey).
This technique was used at Woolsthorpe Manor (National Trust) to investigate newly discovered graffiti attributed to Sir Isaac Newton.
