I'm hoping to use the RTI method to image some fossils. The fossils are largely two dimensional with a very shallow relief of at most a few millimetres, and are generally approximately 5 to 10 centimetres long. I was considering doing this by constructing a dome, 25 cm in diameter with a central hole in the top for the camera and then 30-40 holes for light to be shined through. The light would be moved manually between photos. As I understand there is a method of doing an RTI without using reflective spheres, but this requires a file containing the different light positions. How are these light positions calculated?
Any other advice on how best to photograph these specimens would be more than welcome. Thank you.