Digitisation of a 12th-century Serbian manuscript

The Miroslav Gospel digitisation project

The Serbian Academy of Sciences and Arts (SASA), as Serbia’s leading scientific and cultural institution, received a proposal from the Ministry of Culture to digitise the most important Serbian manuscript of the 12th century, the Miroslav Gospel. The digitisation was to be carried out by the SASA Audiovisual Archives and Digitalization Center (AVA SASA). Two other institutions also took part in the project: the National Museum, where the manuscript is kept in a specially designed room, and the National Library of Serbia, which is officially responsible for the manuscript. In April 2021 the four institutions concluded a formal agreement on the digitisation.

Before the agreement was signed, AVA SASA carried out detailed preparations lasting about a month. Once the preparations were complete, the Miroslav Gospel was digitised at the National Museum between 23 June and 10 September 2021.

Detail from the first page of the Miroslav Gospel with the three evangelists (John, Mark and Luke). The absence of the fourth evangelist (Matthew) remains unexplained.

The significance of the Miroslav Gospel manuscript

The Miroslav Gospel is the oldest surviving written monument of Serbian cultural heritage and was included in UNESCO’s Memory of the World Programme in 2005. It was made in 1180 on the commission of Miroslav, Prince of Hum and brother of Stefan Nemanja, Grand Prince of Serbia. For seven centuries it was kept in the library of Hilandar, the Serbian monastery on Mount Athos. In 1896 it was donated to King Alexander Obrenović of Serbia. During the First World War it was evacuated across the Albanian mountains with the retreating Serbian army, and at the end of the war it returned to Belgrade.

As a gospel book it has a liturgical structure, with the text arranged according to the readings of the liturgical year. It is written on parchment and consists of 181 leaves (362 pages). The manuscript measures 41.8 x 28.4 cm. Richly decorated initials and miniatures appear on almost every page, some of them adorned with gilding as well. In total the codex contains 323 initials and miniatures, some of which can be as large as 20 cm.

It is currently kept in the National Museum in Belgrade, and the Audiovisual Archives and Digitalization Center of the Serbian Academy of Sciences and Arts digitised the Miroslav Gospel.

Two pages of the Miroslav Gospel with initials and miniatures, some of which are also decorated with gilding.

Initials and ornamentation

A distinctive feature of the Miroslav Gospel manuscript is its Romanesque-style initials and illuminations, based on Byzantine traditions. It contains initials typical of Romanesque-period miniatures as well as initials of Byzantine origin. This work is one of the most important witnesses to the mutual interplay of Western and Eastern artistic influences in the 12th century.

The illuminations and initials of the Miroslav Gospel are among the finest examples of Serbian medieval book decoration. Each is richly decorated with ornamentation, woven from two or more interlaced bands, or the outlines of the letters are clearly visible in a tangle of leaves. There are also initials decorated with animals, masks and human figures, sometimes embellished with gold applications.

Detail with an illumination and an ornate initial.

The digitisation process: exploring the challenges and solutions

The preparations and trials for digitising the Miroslav Gospel lasted a month. The manuscript was digitised in the following variants:

• Both pages at once, as an unbound book, lit by two LED panels;
• Each individual page lit by two LED panels;
• Each individual page lit by a single LED panel;
• Each initial and illumination lit by two LED panels;
• Each initial and illumination lit by a single LED panel.

Although this procedure does not comply with the FADGI recommendations, digitisation with a single LED panel provides more information about the structure of the parchment and the graininess of the paint (see the lower image).

Detail of an illumination captured with two LED panels and with one. The original detail measures 1.7 cm.

Camera settings for maximum sharpness and for preserving page size

In order to achieve the highest standards in the digitisation of cultural heritage, AVA SASA decided to acquire Phase One solutions, following the example of the world’s most important archives and museums, which use this equipment to digitise their materials.

Every variant of the digitisation of the Miroslav Gospel was captured with a Phase One iXG 100 MP camera. The photographs of the open double-page spread and of the individual pages were taken with a Schneider Kreuznach 72 mm iXG lens, and those of the initials and illuminations with a Schneider Kreuznach 120 mm iXG lens.

For the open double-page spread, the camera was fixed at a height of 107.5 cm. After two pages were captured, the camera height was lowered to maximise sharpness and to preserve the page size. The same procedure was applied to the individual pages, with the camera starting from a height of 76 cm. For the photographs of the initials and illuminations taken with the macro lens, the starting height of the camera was 69 cm.

PHASE ONE iXG 100 MP with a Schneider Kreuznach 72 MM iXG lens for photographing single and double-page open books

Flattening the parchment leaves

Because of the binding of the Miroslav Gospel, it could not be taken apart during digitisation. This caused the following problems:

a) The parchment is wavy and fragile, and the leaves are generally not lying flat. b) Some initials and illuminations are sunk into the binding, so they require careful handling when the book is opened in order to become visible.

The challenge of flattening the page cannot be solved with the usual glass plate, since physical contact with the parchment is prohibited.

For this reason, specially designed Plexiglas rods were made to achieve the correct alignment. The strength of the pressure and the stability of the rods are regulated by Plexiglas boxes containing larger rods. In this way the parchment leaves can be flattened with an innovative combination of Plexiglas rods and plush-covered lead weights.

Flattening a parchment leaf with specially designed Plexiglas rods and plush-covered lead weights

How the gilding was captured,

to reproduce the lifelike appearance of real gold

Many of the initials and illuminations of the Miroslav Gospel were made with gilding. The lighting of the page on which these appear requires special attention, since gold is a metal with its own structure and brilliance. In other words, the photograph must clearly convey that it depicts gold, not merely the colour yellow.

Using an extremely sensitive camera when photographing gold carries the risk that parts of the gilding will be “burnt out”, meaning that a white surface may appear in areas of strong reflection. On the other hand, toning down the lighting by reducing the intensity of the LED panel or changing its angle may cause the gold surface to sink into shadow, thereby losing the information that the material is in fact gold.

To solve the problem, tests were carried out to determine how gold appears when the Miroslav Gospel is photographed. The tests were performed on a volume of Diderot’s Encyclopédie, which is similar in size to the Miroslav Gospel. For this purpose, thin gold-metal foils of the kind used for gilding were placed on different parts of the page. In a series of tests in which the angle of the LED panel was varied, optimal lighting was achieved so that the gilding is neither too reflective nor lost in shadow. The exact distance and angle (45 degrees) of the LED panels proved decisive for a satisfactory result.

Experiment with thin gilding foil to simulate the gilding of the initials and illuminations of the Miroslav Gospel

Maintaining constant sharpness and page size

A number of problems had to be solved when digitising the Miroslav Gospel. The primary task was to ensure a constant scale of the pages, since the book is 8 cm thick, and with every page photographed the thickness decreases, as do the page size and the sharpness of the photograph.

However, the traditional methods of checking sharpness and size were somewhat limited by the requirement that the Miroslav Gospel be digitised in low light, in live view. The AVA team therefore had to find a non-standard solution.

This problem was solved with guides fixed on a secondary monitor. By fine-tuning the camera height, the edges of the page always stayed exactly within the frame of the guides, so the image was perfectly sharp.

Photographing the initials and illuminations was a particular challenge. Since their sizes vary, in order to achieve a realistic size relative to the other initials/illuminations, a guide frame was fixed on the secondary monitor, with its dimensions determined on the basis of the largest initial (20 cm high) /the dark part of the upper image/. Two further crossed guides mark the centre of the guide frame, where the initial/illumination to be photographed is placed (blue guides in the lower image).

Since the initials and illuminations were photographed with a macro lens (120 mm), and the unevenness of the parchment surface stands out more when the capture area is smaller, the following solution was used. Two further guides were placed on the secondary monitor two centimetres apart (red vertical guides on the left in the lower image), using a ruler placed next to the surface of the initial/illumination to be photographed. By fine-tuning the camera height, the objects were captured only when the two guides aligned exactly with the divisions of the ruler (2 cm). This ensured the perfect sharpness of the photograph.

The guides shown on the secondary monitor (live view) in the upper image ensure a constant page size; the lower image shows checking the size and depth with a ruler

Quality control was of paramount importance from the outset.

Before the Miroslav Gospel is photographed, the GT (Golden Thread) test image is checked in the ISa software. The evaluation covers seven parameters, each with four grades (stars). Photography begins when all seven parameters receive the highest rating (four stars). The highest rating was achieved within the Metamorfoze standard, and also when using the LCC (lens distortion correction) profile, with two LED panels in use.

After photography, a detailed visual quality check of all details (corners and centre) is carried out on the iMac screen, with the photograph magnified by up to 400%. Capture of the next page begins only after the magnified photograph has been thoroughly checked and approved. Each TIFF image is approximately 700 MB, while the JPG image intended for web display is approximately 2 MB.

Quality control with the photograph magnified to 400%.

Crew members:

Project manager: BRANISLAV VOJNOVIĆ (expert at the SASA Audiovisual Archives and Digitalization Center)

Camera operator: JELENA POPOVIĆ (expert at the SASA Audiovisual Archives and Digitalization Center)

Camera operator: STEFAN VLASTIĆ (expert at the SASA Audiovisual Archives and Digitalization Center)

Manuscript handler: ŽELJKO MLADIĆEVIĆ (curator at the National Library of Serbia)

Video clip: BORIS MILJKOVIĆ