Sometimes the ambient light level is too low for successful for photography, or it’s the ‘wrong’ kind of light. This is where photographers turn to flash (or ‘strobe’, if you’re in the US). Flash works by emitting a very short, very powerful burst of light. Energy is stored in a capacitor in the flash head […]
Flashguns usually offer automatic TTL (through the lens) exposure. This means you don't need to carry out any complex flash calculations because he camera can measure the light from the flash as it fires and adjust the duration to give the correct exposure.