ARCHiOx, part 2: Digital imaging within a tradition of facsimile-making

ARCHiOx is by no means the first technology to create facsimiles of ancient texts or images. The process of copying using pinholes is evident on the largest original which has so far been captured for the ARCHiOx project. Dating to the 14th century, the Gough Map is one of the earliest maps to show Great Britain in a geographically recognisable form and served as a blueprint for maps of Britain for over 150 years.

Oblique images of the sign marking the location of Hull, East Yorkshire. Left: albedo. Right: shaded render showing the micro topography of this area of the map, in the absence of the original’s colour. Tiny indentations marking the form of the sign provide evidence that the map was copied from a precursor map. MS. Gough Gen. Top. 16.

Bequeathed to the Bodleian Library by Richard Gough (1735-1809), the map is covered in over two-thousand tiny indentations which transferred the position and form of geographical features from a precursor map.  Through studying these pinholes, researchers may be able to determine which features would have been present on the precursor map and in doing so, estimate when it may have been made.

This historic map has been recorded numerous times since its creation.  It therefore serves as wonderful case-study in the development of copying and imaging techniques.  A copper printing plate was engraved in 1780, prints from which are held in the Bodleian’s collections. Using a novel reproduction method developed at the Ordnance Survey, a photozincography recording was made in 1871.  In 1958, a run of collotype prints of the Gough Map were made at Oxford University Press.   The map was recorded digitally for the first time in 2006.  Hyperspectral and 3D laser recordings followed nine years later, in 2015.   These initial 3D recordings were conducted by the Factum Foundation’s Head of 3D scanning, Carlos Bayod.

“The recording carried out in 2015 applied the Lucida 3D Scanner to capture for the first time the topographical characteristics of this unique map. One of the first collaborations between the Bodleian Libraries and Factum Foundation, this survey allowed us to see and measure the shape and surface of the map without the colour layer, making it much easier to allocate the distribution of the pinholes, among other marks present on the relief. The information captured by the Lucida systems offers the possibility of visualizing the map’s surface on-screen as a shaded render, an image format onto which it is possible to register other layers of information such as the colour photographs. Additionally, it creates a greyscale depth map that can be used for re-materializing the data as an accurate physical reconstruction, becoming the base for creating an exact facsimile”. Carlos Bayod Lucini, Head of 3D Scanning, Factum Foundation

The new photometric stereo recording of the Gough Map captured with the Selene, was captured in June, 2022. MS. Gough Gen. Top. 16.

The photometric stereo captures made for ARCHiOx are the highest resolution recordings of the Gough Map to date.  Both the front and reverse of the map were recorded at over 700,000 pixels per square inch.  In order to record the map at this resolution, 85 image tiles were captured, processed and stitched together to form a single image.  Prominent pinholes and scoring marks are clearly visible from the recordings. These have been analysed, using geographical information system software by Damien Bove, Researcher for The Gough Map Project and Picture Editor of Imago Mundi: International Journal for the History of Cartography

“The pricking on the Gough Map is key to its creation, marking the location and form of place signs copied through from a precursor map. Where the tool has been pressed through the skin, it has left holes. Most of these can be seen on high resolution photos and on the earlier Lucida scan. Where the tool was pressed with less force, however, it has left only small depressions. The ARCHiOx scan has allowed us to identify and measure these for the first time, giving us a fuller understanding of the earlier map.” Damien Bove, Researcher for The Gough Map Project and Picture Editor of Imago Mundi: International Journal for the History of Cartography.

Visitors examine a three-dimensional facsimile of the Gough Map, made by Factum Arte, following a presentation given by the Bodleian’s Map Curator, Nick Millea.

But the ARCHiOx recording has not only allowed for on-screen analysis.  The data has also been used to create a remarkably accurate three-dimensional facsimile of the map.  Currently installed in the Bodleian’s Map Room, the facsimile provides an opportunity for close examination, ensuring that the original map need not be as frequently transported or removed from its protective casing.

“Facsimiles allow us to have a more natural connection with valuable cultural objects. Thanks to the possibility of reproducing the surface relief and colour in high resolution, a facsimile can serve a triple function contributing to the preservation, study, and dissemination of the original, for the benefit of both experts and amateurs alike”. Carlos Bayod Lucini, Head of 3D Scanning, Factum Foundation

— An essay by John Barrett, Senior Photographer, Bodleian Libraries, about discoveries from the ARCHiOx imaging project, which has been funded by the generous support of the Helen Hamlyn Trust. See also:  ARCHiOx: research and development in imaging – The Conveyor

Download the full essay by John Barrett, Senior Photographer and ARCHiOx Technical Lead (Bodleian Libraries)

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