Feasibility Of Using Digital Photograghy In Dental Colorimetry Research

In this experiment all parameters for digital photography were tested individually and the best combination of parameters was found. Then the influence of the lens, ring-type flash and digital camera body to the exposure was compared and the combinations of lenses ,ring-type flashes and digital camera bodies were tested. All images were processed by Adobe Photoshop CS4 in L~*A~*B~* color space then the Student's t test was conducted. The best combination of parameters was: camera sensitivity ISO100, shutter speed l/200sec, aperture value F22, flash white balance and locking ring-type flash output by FEL function with Kodak Grey Card. The result indicated: different individual of same type of lens and flash caused significant statistic difference to exposure, different type of lenses and flashes cause significant statistic difference to exposure, too. The latest model of camera body gave the best consistency among different bodies produced by the same manufacturer; despite it was not the most expensive model. Canon EOS 450D camera body mounted with Canon EF100mm USM Macro lens and Canon MR-14 ring-type flash was the best combination of equipments for exposure consistency. The experiment indicated it was possible to use digital photography in dental colorimetry if exposure parameters were strictly controlled and equipments are properly combined.