Learn Digital Photography .. Flash Units In Digital Photography
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. Know the basic facts about the difference between built in and external flash units.
Many advances have been made with flash units since the early days of photography. In photography's infancy, flash units were using powder that was lit by electrical current and then "blown up" to generate the light energy. This method was most certainly a risk. It also proved a challenge as the flash units were not automatically in time with the camera's shutter so the photographer had to coordinate the flash to go off at the exact time the photo was shot.
Today flash units have eliminated this challenge. An electronic flash tube ensures flash timing is synchronized to the camera. The photographer now gets to concentrate on other aspects of the photo. New digital cameras can even determine on their own if the flash is even needed, set its intensity and other parameters and fire the flash at the precise time the shutter is opened. All of this is automatically done in the background. Should the user want to make their own adjustments, digital cameras also allow the user to manually control the flash, set its intensity and more.
Flash units are divided into two categories: Internal built-in flash units or external flash units. Internal flash units are built into the camera. Almost all digital cameras include such a unit and allow the user some control 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 support external flash units. Usually the lower end pocket cameras do not allow external flash units while all high end digital SLR cameras do allow such external flash units. External flash units can vary a lot. They can have different light energy levels that they can emit and different mechanical characteristics. Some external flash units also include smart sensors to measure ambient light, distance and other optical parameters in order to optimize the flash effect.
Flash units can be used in both automatic and manual mode in most digital cameras. When in automatic mode, the camera measures ambient light and fires the flash when there is a lack of enough light. There can be times the camera will make the incorrect choice in using the flash and will either fire or not fire the flash when the contrary was needed. Setting the flash intensity is important also. Should the flash unit fire too much light energy on objects that are too close to the camera the digital photo will be washed out. Of course if the flash unit fires a small amount of light energy on an object that is farther away from the digital camera the digital photo will be a too dark.
Flash units do have boundaries. They do not light any view and any object at any distance from the camera. You should know the limitations of your flash unit. As an example, experiment to see what the highest amount of light energy it can produce and at what distance an object can effectively be lit from. Use a tripod with a longer exposure and turn off the flash itself if the object is out of the effective flash range. There can be cases where it is still useful to use the flash even if there is enough ambient light available. In this situation, you can manually fire the camera's flash. This technique is known as fill-in flash and is typically used to fill-in shadowed or darkened areas on objects in the digital photograph.
