Infrared reflectography (IRR) images were captured with an Apollo reflectography camera (Opus Instruments, UK) from the Chinese medical manuscript "Slg. Unschuld 8051", held at Berlin State Library, Germany (15 September 2022). The aim was to obtain an infrared image of the entire bottom edge of the manuscript, since a previous investigation on 20 April 2022 with the help of a Dino-lite microscope (model AD4113T-I2V) with the possibility to switch between VIS, IR (940 nm), and UV (395 nm) light had suggested the presence of writing in carbon ink in that area.

The regular Short-Wave Infrared (SWIR) sensing range (900–1700 nm) of the 128×128-pixel scanning InGaAs sensor was reduced by a Long Wave Pass Filter (LWP1510, range 1510–1700 nm), mounted in front of the IR lens (150 mm, f/5.6–f/45) with the aperture of f/8, acquisition time was 50 ms/tile. The working distance between the sensor and the object was set to approx. 67 cm. Broadband illumination was provided by two 20W halogen lamps.

We cordially thank Dr. Cordula Gumbrecht for her support and assistance in making the necessary arrangements at the Berlin State Library.  

Overview of files in the dataset

Folder "1_Cell_phone_images": Images of the top, front and bottom edge of Slg. Unschuld 8051, captured by Thies Staack with cell phone camera (see metadata in the EXIF header of the image files) (20 April 2022, Berlin State Library). File naming conventions "Slg_Unschuld_8051_[side]".

Folder "2_Dino-lite_images": Infrared images of traces of writing on the bottom edge of Slg. Unschuld 8051, captured by Thies Staack with Dino-lite microscope (model AD4113T-I2V) (20 April 2022, Berlin State Library). File naming conventions "Slg_Unschuld_8051_bottom_[serial number]".

Folder "3_ Opus_Apollo_setup": Images of setup of Opus Apollo infrared reflectography camera captured by Ivan Shevchuk and Thies Staack with cell phone camera (see metadata in the EXIF header of the image files) (15 September 2022, Berlin State Library). File naming conventions "Slg_Unschuld_8051_IRR_setup_[serial number]".

Folder "4_Opus_Apollo_images": Infrared reflectography images of Slg. Unschuld 8051 captured by Olivier Bonnerot, Kyle Ann Huskin and Ivan Shevchuk with Opus Apollo camera (15 September 2022, Berlin State Library). File naming conventions "SLG_Unschuld_8051_[side]_[image processing]".

Explanations on image processing: "NoFilter": Indicates imaging w/o filter "1510LWP": Indicates use of Long Wave Pass Filter (LWP1510, range 1510–1700 nm) "Cal": Indicates calibration based on two round Spectralon diffuse reflectors

The research for this project was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy – EXC 2176 'Understanding Written Artefacts: Material, Interaction and Transmission in Manuscript Cultures', project no. 390893796. The research was conducted within the scope of the Centre for the Study of Manuscript Cultures (CSMC) at Universität Hamburg.