FORS dataset of crouching Anadyomene Venus (114536)

Reflectance spectroscopy is a well-established technique for the study of traditional artworks on parchment, paper, textiles, stained glass/windows, stones, walls, canvas, and panel paintings. It is based on the spectral analysis of electromagnetic radiation reflected from a surface as a means of investigating the properties of surface material. 

The absorptions due to electronic transitions in the broad spectral window from visible to NIR (400-1000 nm), can be exploited for the identification of most of the pigments and the characterization of organic dyes and alteration products. 

Fibre optic reflectance spectroscopy (FORS) spectra in the 350–1000 nm range were acquired using a Tungsten source (Ocean Optics mod. HL200, Ocean Insight, Orlando, FL, USA) and a spectrometer (Ocean Optics mod. HR2000, Ocean Insight, Orlando, FL, USA) equipped with optical fibres. The measuring head with 0° illumination and 0° signal collection allowed the acquisition of the reflectance spectrum of an area of about 2 mm^2.

Each acquired spectrum was the average of 30 scans. As a reference, a Spectralon© plate (WS-1S-L Labsphere certified standard, 99% reflective material, Labsphere Inc., North Sutton, NH, USA) was used.  

The acquired reflectance spectra, handled with OOIBASE software (v. 32), were compared with paint replicas 

Connection of the Y fibers bundle with 0° illumination and 0° signal collection with the in-house measurement head. Calibration of white and black on Spectralon© plate  

Interpretation by calculating the derivative of the spectra and by comparison with the reference dataset of reflectance spectra