Each image below links to a synchronized three-way interactive viewer which compares RGB (~450-750 nm), near infrared (NIR, 750-1100 nm), and NIR fluorescence (750-1100 nm) images for each portrait in this study. The RGB and NIR images provide a general sense of the colorants used and how the portraits were painted. The fluorescence images mainly show the distribution of a single pigment- Egyptian Blue- which exhibits a strong luminescence at ~900nm when excited by visible light.
Zoom can be performed by scrolling with the mouse or by clicking on the button in the upper left hand corner of the image. All images were acquired using a Canon EOS 5D Mark III camera with the IR blocking filter removed. For the both the NIR and NIR fluorescence images, a visible-light blocking filter (750 nm) was placed in front of the lens. Illumination for the fluorescence images was achieved using a flash with a IR-UV blocking filter (visible pass) attached.
All visualizations work on Chrome, Firefox, and Safari browsers.