An external flash is geared for photographers who want to stay mobile. They usually capture fleeting moments such as at press conferences or if you are at a “Live” event. An external flash can also be used to add dramatic lighting to more contemporary-styled portraits.They are light-weight, compact, and less expensive than a studio lighting kit.
Con
External flashes tend to cast a harsh, less subtle light to a scene. They also have a very limited range in how much a scene is illuminated. A diffuser can be used to soften the harsh light, though this cuts down the range of the flash even more.
OUR EXPERTS RECOMMEND THIS FLASH
Canon Speedlite 430EX II Flash for Canon Digital SLR Cameras