Halogens are a group of elements-chlorine, bromine, and iodine-that are combined with silver to form the light-sensitive crystals used in photographic emulsions. These silver halides are the foundation of traditional photographic film and paper.
Understanding halogens is essential for photographers and chemists working with film-based photography, as the type and combination of halides influence film sensitivity, grain structure, and tonal response. Proper use of halide emulsions helps achieve precise exposure and high-quality photographic results.