Photography and Photogrammetry at the Garstang

Professor John Garstang was a prolific photographer, and if there is one thing that the Garstang Museum has, it’s photographs! A lot of the pictures in our archive were taken by John Garstang himself during his excavations. Photographic documentation in archaeology wasn’t common practice at the time, making these archival entries all the more important. They are not just pictures of the artefacts and the sites from which they came, but of the people involved in the excavations, and even the odd candid snap of his life surrounding his work.

Today, documenting artefacts and sites via photography is an important step not only in the excavation process, but also in curatorial work. It allows us to digitally preserve images of artefacts that may be too fragile to handle, provide a way for the general public to view objects that they are unable to visit in person, and analyse the excavation processes of past excavations and even sites that no longer exist.

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Digital Archive Photograph from John Garstang’s Excavations at Meroë

Focus Stacking

The Garstang Museum has been working with Retrograde Photography to get some high-quality images of our objects for use in new displays and exhibits. One of the techniques used is called “focus stacking”. When getting very close to small objects for detailed photography, the focus range can be quite small, causing focus to “drop off” very quickly. Focus stacking involves taking a large number of photographs of the same object with different parts in focus, and then digitally combining these images to create a photograph of the object with every single part in perfect focus. The results are quite impressive!

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Hedgehog amulet photograph, courtesy of Retrograde Photography (E.207)

Photogrammetry

Technology has moved on from the simple photograph. A technique called photogrammetry is something that the Garstang Museum has begun exploring over the last couple of years. At its most basic it involves taking a series of high quality photographs of an item at different angles. This is achieved by placing the item on a turntable and moving it around in small increments, until the entire circumference of the item has been digitally captured. A series of ‘targets’ are placed on the turntable prior to photographing. They provide fixed points on the images, so that once the pictures have been taken they can be uploaded onto a computer and special software can pinpoint these fixed points. These fixed points then allow the software to turn those 2D images into a 3D model.

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Ardern, one of the post-doctoral researchers at the University of Liverpool, teaching the team about photogrammetry.

The availability of this technology means that objects that are too fragile to normally handle can be manipulated and studied. Most importantly, members of the public can interact with artefacts in a way that they previously haven’t been able to; artefacts normally behind cases and only viewed from one angle can become items that a person can move around and examine. Objects that are not normally on display for whatever reason could be digitised and uploaded into interactive catalogues for people engage with. The wide reaching implications of museums such as the Garstang being able to utilise photogrammetry technology not only to educate in the public sphere, but also to aid in research pursuits, is incredible. It has the possibility of inspiring new fields of study, revitalising older ones, and bringing the past to life in a manner that is accessible to all.

Sarah McBride (Edited by Chris Bebbington).

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