Variable powered ? do you mean dimming capability or powered from different input voltages? Also shoots 50 watt, really means consumes 50 watt of power from your battery or supply source. A more accurate description would be approximately 800 lumens ( 50 W equivalent filament bulb). If you are doing table top or close up work, that brightness may be adequate. But if you are planning to replace an electronic flash at working distances of over 10 feet, then perhaps something in the 2000 to 4000 lumen range may do.There are very few led units with on-board battery that deliver approx 1800 lumens out there but the color temperature is on the bluish side and can be corrected somewhat with supplied amber or warming filter(s). There are many variables in photography to consider, aperture, F stops, asa and so on. Just keep in mind that if you are planning to find an alternative to the flash, the constant and low output of the leds will limit you considerably to the fast shutter speeds that the flash units offer.I use leds for still life shots when there is no subject movement that allows slow shutter speeds.I really do not advise leds for photography work that involves shutter speeds in the 1/125 and faster range unless the subject is 3 feet or less from the led.As a fill light for available light, definitely. I would try before I buy, especially at the high prices of pro quality units.
