Film used in photography represents one of the oldest industrial uses of iodine. All forms of non-digital photography that still involve films, are based on the light-sensitive properties of silver halide crystals, chemical compounds of silver and halogens. Photographic films contain those crystals within a thin layer of gel, forming a photo-sensitive emulsion where, with light incidence, image is recorded. Also, this chemical process applies to radiographic films for X-ray procedures.


Cesium iodide has the ability to absorb X-rays, gamma and particle radiation, emitting visible light. This so-called scintillation effect is used in medical diagnostics, exploration for natural resources and in nuclear physics research.