Ortokromaattisten

Ortokromaattisten is the genitive plural form of the Finnish adjective ortokromaattinen, meaning orthochromatic. In optics and color science, ortokromaattinen describes materials, emulsions, or systems that have limited sensitivity to certain wavelengths of light, typically with reduced or negligible response to red light. The term is primarily used in historical and technical contexts related to photography, cinematography, and imaging.

In historical photography and early color science, ortokromaattiset materials were sensitive mainly to blue and green wavelengths, rendering red tones as darker grays. They produced distinctive tonal renditions compared to later panchromatic materials, which are sensitive across the full visible spectrum. Orthochromatic designs were gradually supplemented or replaced as imaging technology evolved toward broader spectral sensitivity.

In Finnish texts, ortokromaattisten is used when referring to several orthochromatic items in a genitive or relational sense, such as ortokromaattisten filmien ominaisuudet (the properties of orthochromatic films) or ortokromaattisten kalvojen kehitys (the development of orthochromatic films). The term remains technical and is most commonly found in historical sources, photography handbooks, and color science discussions.

Etymology and related terms: ortokromaattinen derives from Greek roots related to straight or proper color, and croma refers to color. Related concepts include ortokromaattisuus (orthochromaticity) and the broader distinction with pancromatic materials, which have sensitivity throughout the visible spectrum.

See also: ortokromaattinen, pancromatic, spectral sensitivity, photographic emulsion, color science.