All cameras have a shutter mechanism to expose the sensor for exactly the right amount of time. The shutter opens to begin the exposure and then closes again to end it. Most cameras have mechanical shutters, though you can also get electronic shutters, which we’ll come to a little later. Mechanical shutters come in two […]
Flash sync speed
Digital SLRs and compact system cameras use focal plane shutters and these have a design limitation – there is a maximum speed at which the whole sensor is exposed at once. This is the maximum flash synchronisation speed. Beyond this, the sensor is exposed in a moving strip, which is no good for flash.
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 […]