Stereoscopic optical measurement of transverse vibrations in the ancient art of Wayang Kulit

Wayang Kulit is the ancient Indonesian art of leather shadow puppetry that is listed by UNESCO as an intangible cultural heritage of humanity. In a Wayang Kulit performance, a master puppeteer applies transversal vibrations on the leather puppets to create life-like motions of the shadow images. We develop a stereoscopic measurement method, based on anaglyph optical instruments, which is suitable for measuring the transversal vibrations of the leather puppets. Our instruments comprise a pair of color-filtered light sources, a cloth screen, a digital camera, and a computer for performing digital image analysis. Our stereoscopic measurement method is useful, not only for humanities scholars who wish to quantitatively study leather shadow puppetry, but also for engineers and scientists who need to measure the transversal vibrations of other thin structures.