Multispectral imaging - near infrared photography (IR)
Analytical technique description:
The technique belonging to the multispectral photographic techniques, called imaging. It is a non-invasive and portable method of analysis for objects of art. It could be used for characterization of pictorial material, identification of pigments and in some cases the study of drawing. As ultraviolet photography, infrared radiations was sent on the surface of the object which can absorb or reflect the radiation, according to material and substances on it.
This technique can goes deep into layers given information on a presence of drawing, depending on thickness and materials.
Applications:
Pigments on every surface especially frescos, canvas and panels.
Basics:
The spectral range analysed is from 730 nm to 1000 nm (camera sensor limit). Diffusion of light, as scattering, decrease with the use of long wavelengths. This phenomena make pictorial layers transparent to the radiation..
Instrumental details:
Canon EOS 400D, Flash Quantum mod. T5D, Schneider Optics B+W 093 IR filters (Florence Unit).
ICVBC - AREA DI RICERCA CNR DI FIRENZE
Via Madonna del Piano, 10 - 50019 Sesto Fiorentino (FI)
Tel. 055 5225484 - Fax 055 5225483
Institute for the Conservation and Valorization of Cultural Heritage