Term - Joule (Watt-second)
|Joule (Watt-second)||SWPP Photographic Glossary|
Wednesday 22nd September 2021
Indicates the energy content of the storage capacitors in an electronic flash. One Joule is the light output given by one watt burning for a second. Therefore a flash unit with a storage capacity of 300 Joules can supply the power to light a 300W lamp for one second. It doesn't take into account any electrical loss between the flash capacitor or flash tube, or the efficiency of tube and reflector.
Information provided by: SWPP