Editing Ultraviolet (section)

===Incandescent lamps===
'Black light' [[incandescent lamp]]s are also made from an incandescent light bulb with a filter coating which absorbs most visible light. [[Halogen lamp#Spectrum|Halogen lamps]] with [[fused quartz]] envelopes are used as inexpensive UV light sources in the near UV range, from 400 to 300&nbsp;nm, in some scientific instruments. Due to its [[black-body spectrum]] a filament light bulb is a very inefficient ultraviolet source, emitting only a fraction of a percent of its energy as UV, as explained by the [[black body spectrum]].