Photography

Flash

Often due to the limitation of the camera's sensor, taking pictures on a poorly lit environment will produce a noisy and often unuseable image. The flash is an accessory that will provide the necessary illumination to compensate for poor lighting.

In Photography, a Flash is a device that produces an instantaneous burst of artificial bright light (typically around 1/1000 sec to 1/200 sec) to provide the subject with momentary illumination. Most modern cameras use Xenon Flash which works by applying a high voltage electrical discharge to a tube filled with Xenon Gas. This produces an electrical arc which emits a short flash of light.

Most low-end cameras come with built-in flash which are sufficient to illuminate subjects of up to 3 meters away. Beyond this range, the flash is often too weak to properly illuminate the subject and provide enough detail on the captured image. It is always adviseable to stay within this range when using simple camera flashes in order to produce acceptable images.

Some cameras have variable flash intensities which can be set using simple controls in the camera. This is useful when taking photographs of subjects from various distances. When taking a solo picture of a nearby subject for example, a softer flash would be adequate while a stronger flash would be needed for a group picture at a farther distance. It is recommended that you take sample shots and get acquainted with the the range of the different intensities so that you will avoid overexposing or underexposing your subjects.

One very important feature that is built into most cameras is the Red-Eye Reduction. The "Red-Eye" effect happens when taking photos with a built-in flash that is very near the lens of the camera. The light from the flash passes through the blood-rich area along the iris and bounces back before the pupil can contract. This is captured by the camera and shows as a red area in the center of each eye. If the Red-Eye reduction is turned on, the camera flashes before the shutter is released to allow the iris to contract and flashes again to take the picture. This generally does not illiminate the Red-Eye effect but it does reduce it significantly even to a point where it is almost unnoticeable.

For professional photography, most high-end cameras like SLRs can use an external flash connected either through a standard mount called a "hot shoe" or controlled by remote. With a variety of External flash available in the market today the problem with low intensity and red-eye are easily solved. Often, using flash on a large group or a far subject is not only solved by using a high-intensity flash unit, rather several flash units are positioned properly and controlled to fire together. Some would often use reflectors and diffusers to control the spread of the light coming from the flash. This offers an advantage of a more balanced lighting making the illumination and shadows look natural. The fact also that the external flash can be positioned anywhere, right away solves the problem with red-eye as the flash can be positioned at an angle such that the reflection from the eye will not be directed to the camera.