Practical notes on ultraviolet technical photography for art examination

This paper discusses two technical photographic methods based on the use of ultraviolet sources for art examination: ultraviolet fluorescence (UVF) and ultraviolet reflectance (UVR). While the UVF technique can be carried out with any digital camera, UVR images are acquired with a digital camera modified to be full spectrum, and thus sensitive into the UV region of the spectrum until about 360 nm. This modification involves the removal of the in-built hot mirror filter on the CCD or CMOS sensor, rendering it sensitive to ultraviolet and infrared radiation. This paper illustrates the procedures and the equipment needed for these technical photographic methods, discussing case studies and results on prepared samples.