Film recorder
From Wikipedia, the free encyclopedia
A film recorder is a graphical output device for transferring digital images to photographic film.
The simplest film recorders typically work by displaying the image on a grayscale cathode ray tube (CRT) placed in front of a photographic camera.
For color images, the red, green, and blue channels are separately displayed on the same grayscale CRT, and exposed to the same piece of film through a filter of the appropriate color. (This approach yields better resolution and color quality than one could obtain with a color CRT.) The three filters are usually mounted on a motor-driven wheel. The filter wheel, as well as the camera's shutter, aperture, and film motion mechanism are usually controlled by the recorder's electronics and/or the driving software.
Higher-quality film recorders called LVT (Light Value Transfer) use lasers to write the image directly onto the film, one pixel at a time. This method is better suited to print to large-format media such as poster-size prints.
In any case, the exposed film is developed and printed by regular photographic chemical processing. Self-developing (Polaroid) film can be used for immediate feedback.
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[edit] Formats
Film recorders are (or were) available for a variety of film types and formats.The 35mm negative film and transparencies are popular because they can be processed by any photo shop. Single-image 4x5 film and 10x8 is often used for high-quality, large format printing.
Some models have detachable film holders to handle multiple formats with the same camera.
[edit] Uses
Film recorders are used in digital printing to generate master negatives for offset and other bulk printing processes. They are also used to produce the master copies of movies that use computer animation or other special effects based on digital image processing.
For preview, archiving, and small-volume reproduction, film recorders have been rendered obsolete by modern printers that produce photographic-quality hardcopies directly on plain paper.
Film recorders were also commonly used to produce slides for slide projectors; but this need is now largely met by video projectors that project images straight from a computer to a screen.
Film recorders were among the earliest computer graphics output devices. See, for example: IBM 740
Nowadays, film recorders are primarily used in the motion picture film-out process for the ever increasing amount of digital intermediate work being done. Although significant advances in large venue video projection alleviates the need to output to film, there remains a deadlock between the motion picture studios and theater owners over who should pay for the cost of these very costly projection systems. This, combined with the increase in international and independent film production, will keep the demand for film recording steady for at least a decade.
[edit] Key Manufacturers
Traditional film recorder manufacturers have all but vanished from the scene or have evolved their product lines to cater to the motion picture industry. DICOMED was one such early provider of digital color film recorders. Arri produces the Arrilaser line of laser-based motion picture film recorders. Celco makes a line of CRT based motion picture film recorders. Lasergraphics is the latest entrant into the cine film recorder market with its twenty year history of dominance in the traditional film recorder business. Lasergraphics this year, 2006, has reintroduced special order production of still film recorders. CCG, formally Agfa film recorders, has been a steady manufacturer of film recorders based in Germany. In 2003 CCG introduced the first motion picture film recorder utilizing LCD technology, Definity, distributed by Digital Film Systems.
Polaroid was a significant producer of film recorders. The top model film recorder that Polaroid produced was the ProPalette 8000 series. Polaroid does not make film recorders any longer. The last LVT machines produced by Kodak / Durst-Dice stopped production in 2002. There are no LVT film recorders currently being produced.
[edit] History
- Before VTRs were invented, TV shows were recorded to film, for archive and later broadcast on a Kinescope.
- In 1967 CBS Laboratories had a shortly a Electronic Video Recording unit.
- All types of CRT recorders were and are used for Film recording. Like the 1954 IBM 740 CRT Recorder.
- Later (1970 and 80s) recording to B&W 16mm film was done with a 3M Film Electron Beam Recorder-EBR.
- Image Transform in Universal City used specially modified 3M Electron Beam Film Recorders that could be film out color 16mm by using three 16mm frames in a row, one Red, one Green and one Blue. The film was then printed to color 16mm or 35mm film. The video was NTSC, PAL or SECAM. Later Image Transform used specially modified VTRs to record 24 frame for their "Image Vision" system. The modified 1 inch type B videotape VTR would record and play back 24frame video at 10Mhz bandwidth, twice NTSC resolution. Modified 24fps 10Mhz Bosch Fernseh KCK-40 cameras were used on the set. This was a custom pre HDTV video System. Image Transform had modified other gear for this process. At its peak this system was used to make "Monty Python Live at the Hollywood Bowl" in 1982. This was the first major DI digital intermediate post production using a Film recorder for Film out.
