Work

The Orbitoscope, a six-axis macro-imaging robot for photogrammetric 3D-digitization of insects and other small specimens

Year: 2026

Type: article

Abstract: Natural history collections contain vast numbers of small, fragile specimens whose morphology is difficult to capture using conventional 2D-imaging. Photogrammetric 3D-reconstruction from multi-view photographs can preserve surface colour and enable scaled measurement, but at macro magnification it typically requires dense viewpoint coverage with high overlap and extended depth-of-field (EDOF) imagery. Existing robotic systems often achieve viewpoint variation by rotating and tilting the specimen, which can be limiting for elongated, heavy, or fragile mounts and for objects whose geometry may change when reoriented. We present the Orbitoscope, an open-source six-axis macro-imaging robot that keeps the specimen stationary while moving the camera in translation (X-Y-Z) and orientation (A-B) around it, with a dedicated stacking axis (C) to acquire focus stacks automatically. We demonstrate the workflow by digitizing six insect specimens and generating scaled, textured 3D models suitable for preservation, measurement, and online dissemination. Basic measurement validation on one specimen showed a mean absolute percent error of 0.52% (max. 0.88%) relative to calibrated microscope reference measurements. Hardware, software, and documentation are openly released, with detailed build and operation instructions archived separately as a technical package.

Source: ZooKeys

DOI: 10.3897/zookeys.1277.177740

Authors: Toivo Aukusti Ylinampa, Urmas Kõljalg

Institutions: University of Tartu, University of Tartu Natural History Museum and Botanical Garden

Language: English

Topic: 3D Surveying and Cultural Heritage

Subfield: Geology

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $754

Funders: European Commission, Eesti Teadusagentuur, Tartu Ülikool