Digital Camera Flash Units
Posted on August 18, 2008
Filed Under Digital Cameras |
Flash units will come in many different shapes and sizes in the world of digital photography. Those cameras on the lower end typically come with built in flash units. High end digital SLR cameras can accommodate sophisticated external flash units. These units can provide maximum lighting in difficult situations. Knowing the facts about flash units and their capabilities, both built in and external are important.
In the early days of photography, flash units were much different indeed. They once consisted of powder that was lit by an electrical current and then literally “blown up” to produce a flash of light energy. This method was both dangerous for the photographer and difficult to manage as the flash units were not automatically designed to go off at the exact moment as the camera’s shutter. The task of ensuring the two went off together rested on the photographer.
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 where the user can set all of the same features to their specifications.
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.
Both automatic and manual flash unit modes are made available on digital cameras. In automatic mode the camera measures ambient light and fires the flash it deems not enough ambient light is present. There can be times the camera will make a mistake in using the flash and will either fire or not fire the flash when the opposite was needed. Keep in mind the importance of setting the flash intensity. 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. 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 then 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.
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