When digital imaging employs a photographic technology and medium (photographic paper, 35mm film, or 4x5 transparencies, for example) it involves exposing the medium with red, green, and then blue light with a CRT (Cathode Ray Tube). The medium then undergoes regular photographic chemical processing.
In recent years, digital projection, the projection of images straight from a computer to a screen, has rendered digital imaging to 35mm transparencies nearly obsolete. Another development, the ability to image directly to photographic paper without the use of transparencies as an intermediary, has further contributed to the obsoleting of digital imaging to transparent film.