solid state darkroom lighting - LEDs as light source

solid-state dark room lighting elektor october 1983 LEDs are normally only used in those applications for which they were designed: as indicator or control light. A rather less usual application is their use as light source in a dark room. solid-state dark room lighting LEDs as light source Using one or more LEDs for dark room lighting is not as odd as may appear at first sight. Particularly not when you consider the advantages over conventional lighting. â–  Because of the well-defined spectral colours of LEDs, filters are not necessary. â–  LEDs are usable when work is carried out on black and white paper, multi-grade paper, colour negative paper, and ortho- chromatic materials. â–  The life of LEDs is not shortened by continuous on/off switching. â–  LEDs do not produce heat. â–  LEDs do not radiate infra-red rays. Of course, a standard LED does not give as much light as a conventional lamp, but this problem could be overcome by the use of more than one LED. This article descri...