Infrared Fluorescence Photography (IRF)
Infrared Fluorescence photography is a useful method for the examination of works of art and archaeology. It is part of the Technical Photography documentation and allows to detect Egyptian blue and cadmium-based pigments.
Infrared Fluorescence phenomenon
Some molecules and minerals (among them mineral pigments) exhibit Infrared Fluorescence. This phenomenon is similar to Ultraviolet Fluorescence where a beam of ultraviolet light produces visible light emission. In the case of infrared fluorescence, a beam of visible light generates an emission of infrared radiation.
Infrared Fluorescence is observed in few rare minerals but also in a very common molecule, chlorophyll. Chlorophyll emits infrared fluorescence in the very near infrared. Indeed, its fluorescence is brighter in the IRF 850 image – where the 850 nm filter was used, allowing through the closest infrared. Notice that, on the other hand,the infrared fluorescence emission of the cadmium red swatch is almost unchanged since it happens at longer wavelength (over 850 nm ).
Applications in Art examination
Experimental Set up
We need a source of Visible only-light and the camera set up for IR photography.
|Publications on Infrared Fluorescence photography (IRF)
|A. Cosentino "Infrared Technical Photography for Art Examination” e-Preservation Science, 13, 1-6, 2016.
|A. Cosentino “Identification of pigments by multispectral imaging a flowchart method” Heritage Science, 2:8, 2014.
|A. Cosentino, S. Stout "Photoshop and Multispectral Imaging for Art Documentation” e-Preservation Science, 11, 91–98, 2014.
|A. Cosentino "Effects of Different Binders on Technical Photography and Infrared Reflectography of 54 Historical Pigments” International Journal of Conservation Science, 6 (3), 287-298, 2015.