Reflectance Transformation Imaging (RTI) is a photographic method that captures a subject’s depth, shape and colour to reveal highly detailed surface information invisible under normal examination.
Images are created from multiple photographs of a subject, where each shot is taken with light projected from a different direction to produce varying highlights and shadows. These are then combined so the changing interplay of light and dark discloses fine details of the surface.
RTI can be useful for many applications, but particularly great for textured art, archaeological or historic artefacts, relief sculptures and other detailed items of interest.
The resultant images give the viewer control over the lighting angle so that minor surface irregularities or significant texture details can be studied at greater clarity. The files can also be embedded into 3D media such as interactive VR galleries that respond to the lighting conditions in a way that a flat 2D copy would not, making the artwork true to its 3d nature.