A single-use bulb containing a fine filament, metal wool or metal foil. The bulbs contents burn up in a flash of brilliant light when an electric current is passed through it, illuminating the scene in a brief flash. Such bulbs obviously cannot be reused.
Flash bulbs were introduced by Vacublitz, a German company, in 1929. They were simple glass bulbs filled with thin aluminum foil and oxygen, and were considerably safer than the dangerously explosive flash powder and magnesium flash sheets that had been used up until then. Even so, early flash bulbs were still dangerous to use - they often exploded inadvertently when exposed to static electricity, and early flash bulbs could also shatter when fired, spraying hot glass onto the horrified subject.
Flash bulb technology improved over the decades and many different kinds were produced. The slow speed at which flash bulbs would burn up yielded shutter synchronization problems and so S (slow), M (medium), F (fast) and FP (focal plane) flash bulbs were all sold at one point - each type having different timings for light output.
Flash bulbs are rarely seen these days, owing to the expense of having to buy new bulbs all the time. However up until the 1980s they were quite commonly used. Particularly with cheap consumer cameras - Flashcube, Magicube and FlipFlash were popular flash products in the 70s. And of course press photographers in Hollywood movies from the 40s and 50s were always seen with their small umbrella-like flash units containing single-use bulbs.
Nowadays even cheap disposable cameras have electronic flash units built in, and about the only people using flash bulbs today are people experimenting with old processes and equipment. (though they are occasionally used for special effects and scientific photography)
cf. flash powder, flash unit, FP, M-sync, Speed Graphic, X-sync.
Entry last updated 2002-04-03. Term 495 of 1487.
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