Eklund, M. J. , A. K. Aase, and C. J. Bell. 2018 Eklund, M. J., A. K. Aase, and C. J. Bell. 2018. Progressive Photonics: Methods and applications of sequential imaging using visible and non-visible spectra to enhance data-yield and facilitate forensic interpretation of fossils. Journal of Paleontological Techniques 20: 1-36. Figure 4: Calcite from the Challenger Cave in Mexico (TMM 10000-2). Images are in A) visible light, yielding off-white color; B) UVA 368 nm wavelength, yielding a fuchsia color; C) UVB 315 nm wavelength yielding a pastel yellow color; D) UVC 254 nm wavelength, yielding a mid-range blue color; E) Combined UVABC radiation yielding a washed-out blue-grey-violet color. The latter reaction cannot be attributed in whole or in part to any particular wavelength, but it is clear that the three wavelengths in combination generate unique visualizations. In our experience, there is no good example of combined UVABC yielding a novel insight on a fossil specimen, but the mineral example shown here demonstrates the possibility. The imaging cube is rotated in each image to document wavelength. Beneath the cube is a card confirming that the camera is imaging full color range in each image, despite differential reaction of the specimen; the card behaves in nearly the same way under each wavelength, demonstrating that the difference in each image is a result of differential fluorescence of the specimen. Lower imaging plate is a pico color calibration target, with full spectrum color return only in visible light.

4A visible light

4B UVA 368nm

4C UVB 315nm

4D UVC 254nm

4E UVA+B+C