Flash units can come in many sizes and shapes for digital photography. Those cameras on the lower end of the scale come with low energy built in flash units.

However, some gear such as the high end digital SLR cameras can accommodate external flash units advanced in their abilities to provide excellent lighting in complicated situations.

The flash units of today are highly developed technology devices. The flash and camera are automatically synchronized using an electronic flash tube taking all of the pressure off of the photographer.

Digital cameras today can determine themselves if a flash is necessary, can set their own intensity and other parameters and can trigger the flash at the precise tine the shutter is opened. All of this is done in the background with no manual effort. For those scenarios calling for a more hands on approach, digital cameras also include a manual mode.

Flash units are separated into two categories:

Internal built-in flash units or external flash units. Internal flash units are built into the camera. Most digital cameras include such a unit and let the user have some management over it through the camera’s menus and buttons.

External flash units are attached to the camera’s body through a dedicated slide-in slot or by using an electrical cable. Not all digital cameras can support external flash units. Some external flash units also include smart sensors to measure ambient light, distance and other optical parameters in order to get the most from the flash effect.