• Twitter
  • Facebook
  • Google+
  • RSS Feed

Friday, November 6, 2009

Just spent a week in the Dogpatch section of San Francisco learning Reflectance Transformation Imaging with Cultural Heritage Imaging. Utilizing traditional digital photographic techniques and a computational photography algorithm, this technique allows for the synthesis of over 36 individual images, each shot with light from a unique incident angle, into a single image file that can be filtered and viewed with control of the light source. The method depends on the use of black spheres that are placed in the mise-en-scene to capture light position by virtue of the highlight that is captured.

RTI files are extremely useful in accessing surface detail of stone and wood surfaces, often revealing elements that are invisible to the naked eye. The process is relatively simple to do in studio and can be adapted to archaeology work in the field as it functions as an alternative means of capturing 3D spatial data that is typically only revealed using laser scanning technologies.

The four day workshop was led by Carla Schroer (pictured in blue) and Marlin Lum (left) at Cultural Heritage Imaging's warehouse location. The instruction was comprehensive and well-paced and allowed for several opportunities to shoot and process RTI files of heritage objects including Roman coins, an aboriginal boomerang, a hand-chiseled spear point as well as a crenelated door frame of an old SF building. Carla and Marlin were incredible instructors and the workshop was a terrific, informative experience, one that I would recommend to other photographers whose work involves archaeology, museum collections or cultural heritage imaging. Yosi R-Pozeilov (far right), photographer for the Los Angeles County Museum of Art, worked with me all week creating light set ups and processing RTI files.

Upon my return to Tampa, I look forward to experimenting with RTI with artifacts from the anthropology department's collection. In combination with photogrammetry, this new skill set should prove invaluable upon upcoming archaeology field work in 2010.

Image courtesy of Marlin Lum/C-H-I
© 2012. Design by Main-Blogger - Blogger Template and Blogging Stuff