Photoflood

Photoflood lamps are a type of tungsten filament lamp designed for use as a continuous light source for photographic purposes. The filaments of such lamps are operated at much higher temperatures than is the case for standard, general lighting service lamps. The result is a brilliance of light much higher than the lamp's wattage rating would suggest. The trade off is that the lamp has a very short service life of seldom more than ten hours.

Applications

Past

Photoflood lamps were used by photographers and film makers as a continuous lighting source. However, for photographers, such use has been overtaken by the use of high power studio flash units many of which also provide a lower power light for modelling purposes. Film makers have turned to longer lasting tungsten halogen lamps which, in their turn, are being overtaken by light-emitting diode (LED) lamps.

Present

Photoflood lamps are still widely used by the motion picture industry. Where an illuminated lamp is required on set as part of the dressing, the light fall from a normal light bulb would not be visible on film as it would be swamped by the bright studio lighting. The ordinary lamp is replaced by a photoflood bulb whose intense light is easily visible on film (and if so required, is bright enough that it can form the sole illumination for the shot).

Lamp characteristics

Photoflood bulbs are available in a number of sizes. The two most common sizes have these characteristics.

Watts	Lumens	Equivalent watts (compared to 100 watt bulb)(Note 1)	Colour temperature (K)	Avg. Life (hours)
250	8500	650	3500	3
500	17,800	1370	2900	8

Note 1:For comparison purposes a 100 watt general lighting service bulb emits a little over 1300 lumens of light.