plate

…then placed it on a plate coated with a light-sensitive solution of bitumen of Judea (a type of asphalt) and lavender oil and exposed the setup to sunlight. After a few hours, the solution under the light areas of the engraving hardened, while that under the dark areas remained soft…

…exposures on sheet films (formerly plates) usually between 4 × 5 inches and 8 × 10 inches. A front standard carries interchangeable lenses and shutters; a rear standard takes a ground-glass screen (for viewing and focusing) and sheet-film holders. The standards move independently on a rail or set of rails…

…producing the first colour photographic plate. He was known for the innovations that resulted from his search for a direct colour-sensitive medium in photography.

Especially sensitive photographic plates are employed to compensate for the low penetrating power of the ions. It has proved possible with these to detect an element over a sensitivity range of one part in one billion. In addition to the sensitivity, a major advantage…

…spectra were recorded with photographic plates or film, in which the film is placed at the image point of a grating or prism spectrometer. An advantage of this technique is that the entire spectrum of interest can be obtained simultaneously, and low-intensity spectra can be easily taken with sensitive film.