Focus-stacked, ultra-macro photography: A tool for analysis, diagnosis and recording in bioarchaeology

This study assesses the potential role of focus-stacked, ultra-macro photography in the differential diagnosis of pathological conditions in human skeletal remains.

1. A segment of calcified artery from the remains of a medieval cleric from Staffordshire, UK. 2. The skeletal remains of an eight-year-old child with active rickets from mid-19th century London. 3. Skeletal remains of a Romano-British neonate from Buckinghamshire, UK.

A microscope objective lens was attached, via an extension tube and relay lens, to a digital camera on a motorised focus-stacking rail. Photographs of skeletal elements and calcified arteries were taken at progressively close focal distance, and processed digitally to generate a single, fully focused image.

On-screen magnification of up to ∼Χ1000 is achievable, permitting visualisation of bone modelling units (osteoclastic pits) and osteonal lamellae. The highly magnified images of skeletal remains reveal physiological and pathological changes which are undetectable with conventional macroscopic examination.

Ultra-macro photography facilitates the biological model of differential diagnosis in bioarchaeology and contributes to revised interpretation.

Focus-stacked photography, using microscope objective lenses, is an inexpensive and practical method for detecting, analysing and recording physiological and pathological change in skeletal remains.

Images from only three individuals were evaluated in this study.

Further studies are needed to control for illumination, presentation of contour and accuracy of colour reproduction.