Before revision: Sciography, also spelled sciagraphy or skiagraphy () , is a branch of the science of perspective dealing with the projection of shadows, or the delineation of an object in perspective with its gradations of light and shade .
After revision: Sciography, also spelled sciagraphy or skiagraphy , is a branch of the science of perspective dealing with the projection of shadows, or the delineation of an object in perspective with its gradations of light and shade .