I was asked this question by some friends on a recent trip to Bergamot Station in Santa Monica, CA recently. It is a question I’ve been asked many times so I thought I’d give an answer on the Photo Exchange. The following is a quote taken directly from Wikipedia:
“LightJet is a trademark of Océ Display Graphics Systems, a division of Océ N.V. (the company that acquired Cymbolic Sciences, Inc.) for a process of printing digital images to photographic paper and film, and for the corresponding hardware.
Unexposed silver-halide photographic paper is temporarily fixed on an internal drum, where three digitally controlled lasers simultaneously expose the photo-sensitive emulsion on the paper medium (or back-lit transparency medium) with red, green, and blue light. The amount of light from each laser varies to provide specific color and density values for each pixel imaged to the print. The light-path includes a spinning surface coated mirror mounted on an air-bearing that travels along the axis of the internal drum, thus reflecting the laser light at 90 degrees allowing for a dimensionally consistent round imaging dot across the entire area of the photographic paper. The purpose of this round imaging dot is to maintain edge to edge sharpness on the final print. The print is then processed using traditional photochemical means. After which, the photographic print is handled just as any other photo-print.
Whereas xerography and inkjet printing employ a halftone process and ink to reproduce digital images on paper, LightJet is a photographic continuous tone process rather than halftone or error diffusion which are common on offset press or ink-jet. The device natively supports 24bit RGB raster files, and is capable printing vector based files when fronted by a photographic Raster Image Processor (RIP). Since 24 bit color continuous tone devices use large multitudes of colors, up to 16,777,216, rather than the small number of colors available to 4-color press and 8-color ink-jet type devices Posterization and banding are unlikely from these types of prints when provided with a file of good integrity.
LightJet printers and film recorders are used by a number of professional-level photographic printing firms (located in North America, Europe, Asia, the Middle East and South Africa) and are available via the internet. Most deliver a final product printed on Fujifilm Crystal Archive or Kodak Endura paper in sizes up to at least 4×10 feet (Thompson). Other Silver-Halide based materials can be printed on laser driven devices such as the LightJet.
The original LightJet image recorder was introduced at PMA in 1995. The first version of the product was the LightJet2000, a three-laser continuous-tone film recorder (the selling price was US$195,000). Its maximum image size was 11×14 inches. The LightJet2000 largely replaced the Fire1000 film recorder.
The LightJet5000 large-format printer was introduced at PMA in 1996. The product produced continuous-tone photographic prints and Duratrans up to 50×50 inches. In 1997 a version capable of printing to a dimensional size limit of 50×100 inches was introduced.
The Oce LightJet430 50″ x 120″ photo laser printer was introduced in 2000. The 76″ x 120″ wide Océ LightJet500XL printer was introduced in 2002.”
By Jim McKinniss