Sciography, also spelled sciagraphy or skiagraphy (Greek: σκιά 'shadow' and γράφειν graphein, 'write'), is a branch of science of the perspective dealing with the projection of shadows, or delineation of an object in perspective with its gradations of light and shade. One of the major professional fields that use this technique is the architectural field. In architecture it is defined as a study of shades and shadows cast by simple architectural forms on plane surfaces. Sciography, also spelled sciagraphy or skiagraphy (Greek: σκιά 'shadow' and γράφειν graphein, 'write'), is a branch of science of the perspective dealing with the projection of shadows, or delineation of an object in perspective with its gradations of light and shade. One of the major professional fields that use this technique is the architectural field. In architecture it is defined as a study of shades and shadows cast by simple architectural forms on plane surfaces.