Reflectance Transformation Imaging - a possible alternative to ammonium chloride coating for specimen photography

Abstract

Coating specimens with ammonium chloride for photography has become the de facto standard for publication in palaeontological journals. However, it has several drawbacks such as the risk of damage to the specimen, and it requires access to a laboratory and a certain level of skill to carry out proficiently. This paper presents Reflectance Transformation Imaging (RTI) as a technique that can be carried out using digital photography equipment available to most researchers, museums or labs. The results of the process are compared with conventional photography, ammonium chloride coated photographs and 3D laser scans.