A structured approach to artefact photography
The PHOTARCH method is built upon a set of clear and repeatable principles designed to ensure visual consistency, scientific comparability, and long-term usability of archaeological imagery. Its goal is to make object photography replicable not only within a single institution or excavation, but across collections, countries, and decades. While individual images may appear deceptively simple, each photograph produced under PHOTARCH follows a strict logic regarding lighting, angle, background, and metadata. This page outlines the core principles of the method and the recommended setup for implementation, whether in a museum environment or in the field.
Lighting is at the heart of PHOTARCH. A single fixed light source (key light) is placed at a 45° angle from the object’s side and above (If the object is placed in the centre of a clock face, the primary light source is positioned at 10:00), ensuring consistent modelling of shape and surface. A fill light or reflector is used on the opposing side to soften shadows without eliminating them. The aim is not to create artistic mood, but to produce measurable, interpretable, and repeatable lighting conditions across sessions and objects. The 45° angle allows for standardised shadow geometry, supporting both visual inspection and potential automated shape recognition. Where possible, the light source should be colour calibrated and spectrally neutral.
In PHOTARCH, the top-down (zenithal) view serves as the primary image for presenting the artefact in public databases. This perspective offers clarity, neutrality, and easy comparability — a standardised overview that places all objects on equal visual footing.
A single image rarely tells the whole story. Supplementary angles — including diagonal views that capture form, surface texture, and depth — help researchers and the public understand the artefact’s character more fully. Most objects are photographed in the zenithal view for the hero image, supplemented by cardinal (front, back, left, right) and diagonal angles where needed.
To make multi-angle documentation consistent and repeatable, PHOTARCH uses a spherical grid system. The artefact is placed at the centre of a virtual globe. The camera is positioned along fixed latitudinal bands (labelled A–L) and longitudinal slices (1–12), like hour markers on a clock face. Each image can be tagged by its angle of capture, ensuring that positions can be defined, reproduced, and compared across objects and collections.
This grid supports structured visual documentation, multi-angle comparison, AI-based classification, and long-term reproducibility.
PHOTARCH recommends a pure white background (RGB 255,255,255) for all images. This background serves three primary functions:
Neutral grey backgrounds, often preferred in museum photography, pose challenges in exposure balancing and are frequently removed during editorial processing — a practice that eliminates valuable shadow information and detaches the object from any visual context. White backgrounds streamline the post-processing pipeline and are ideal for multi-platform publishing.
PHOTARCH integrates scale and colour targets directly into the photographic workflow to ensure visual accuracy and reproducibility. However, these reference tools are intentionally excluded from the final hero image — the top-down view that represents the artefact in public-facing databases. Instead, a separate image should accompany each set of images, clearly showing the scale and colour chart under identical lighting conditions. This reference image functions much like a technical specification page in online retail — essential, but not in the spotlight. It should be part of the image set, not part of the showcase. Together, these tools ensure that each image is not merely a visual representation, but a measurable, comparable data point. They allow researchers and viewers alike to interpret artefacts with both scientific precision and visual clarity.
There are numerous guidelines for how to best position a scale in relation to an artefact — but none of them are truly accurate. A physical scale bar, no matter how carefully placed, only confirms the size of the scale itself, not necessarily the artefact. While physical scales are useful for establishing the z-axis and indicating general spatial relationships, they fall short when it comes to precise dimensional accuracy. The only reliable way to define the size of an artefact is to measure it directly, using a calibrated digital caliper with at least two decimals of precision. These measurements should be embedded in the metadata associated with the image. Where database systems allow, a digital scale overlay can also be imposed on the image, visually communicating the artefact’s true size without relying solely on a manually placed ruler. This shift — from analogue reference to embedded measurement — is key to treating the photograph not just as an illustration, but as a trustworthy data point.
By adhering to these principles, the PHOTARCH method provides a robust and adaptable standard for artefact photography. It is designed to serve as a reliable foundation for documentation, analysis, and communication. As the volume of cultural heritage imagery continues to grow, consistency becomes not only a technical concern, but an ethical one. If the past is worth preserving, it is worth photographing properly.