Xochicalco: Tlayohualchieliztli or camera obscura

Research at the UNESCO World Heritage Site of Xochicalco, Mexico, presents evidence that a shaft with a zenith-oriented aperture functioned as a pre-Columbian camera obscura, or tlayohualchieliztli. This would mark the first documented use of an image-forming device in Mesoamerica. The study determined that while the shaft's aperture was too large for pinhole optics, it could have been covered with a screen containing a smaller borehole, optimizing light conditions for celestial observations. Analysis suggests the shaft was oriented to capture images of the sun during daytime and the moon at night, with amate paper or cloth used to record positions. The research combines optical modeling and astronomical alignment studies to support this hypothesis.

Cornejo-Rodríguez, A., Vázquez-Montiel, S., Granados-Agustín, F., Gale, D., Diamant, R., Espinasa-Perena, R., Cruz, J. L., & Fernández-Guasti, M. (2011). Xochicalco: Tlayohualchieliztli or camera obscura. 22nd Congress of the International Commission for Optics: Light for the Development of the World, 8011, 80119O. https://doi.org/10.1117/12.903281