Energy is measured in Joules. 1 Joule = 1 Watt-second. Energy listings are the maximum per-flash energy rating (input to flash tube) for each available model. In the United States, the Watt-second is the customary unit, but this is more awkward than the Joule which is an internationally recognized unit of energy.
Some manufacturers name their models based on "effective" Watt-seconds instead of actual energy input to the flash tube. This takes into account the beam concentrating properties of the permanently attached or removable standard reflector.
Energy delivered to the flash tube provides a relative, not absolute indictation of light intensity versus another flash unit. This is because light intensity depends on many factors including flash lamp design, the application of UV attenuating coatings, diffusers, reflectors, interference from modelling lamps, etc.
| Brand Name | Phone Number | Manufacturer Name / Address | Comments | Monolight / Monobloc Energy (Joules) | Pack and Head Energy (Joules) |
| Alien Bees | 877-714-3381 | AlienBees, Inc. 530 East Iris Drive, Melrose, TN 37204 |
Direct sales only. Sister company White-Lightning makes heavier, more powerful units. Accessories are made in Taiwan. | 160, 320, 640 | - |
| Bowens | |||||
| Calumet | |||||
| Dyna-Lite | |||||
| Elinchrom | 201-818-9500 | Elinca Switzerland |
Sales through distributors only. U.S. distributor
is Bogen Photo Known for short flash duration. 530/750 monolight is rated at 530J with 120V supply, 750J with 230V supply. |
300, 600, 530/750, 1200 | 1200, 1500, 2400, 3000, 6000 |
| Hensel | |||||
| Photogenic | |||||
| Photographers Warehouse | |||||
| White Lightning | 800-443-5542 | Paul C. Buff, Inc. 2725 Bransford Ave. Nashville, TN 37204 |
Direct Sales only. Heavier construction, higher available output than models made by sister company Alien Bees. | 330, 660, 1000, 1320 | - |
