Fremkallere
Fremkallere is a term used in Norwegian photography to designate the chemical solution or reservoir responsible for developing exposed photographic material. In traditional silver-based photography, fremkalleren reduces exposed silver halide crystals in the emulsion to metallic silver, producing a visible image. The process takes place in a darkroom and requires controlled conditions such as temperature, typically around 20°C for black-and-white film, and development time that depends on the emulsion, contrast desired, and developer concentration. The fremkaller is usually supplied as a concentrate to be diluted with water, available as liquid solutions or powder forms that are dissolved before use.
Common families of fremkallere include hydroquinone-based and metol-based formulations, sometimes with phenidone as a substitute; modern
In history, fremkallere became standardized with the rise of practical black-and-white film development in the late