Basic Digital Photography: Getting the Light Source Right

by : Christine Peppler

Lighting is the single most critical factor in determining the quality of any photograph. Although with digital cameras you can edit after the fact, such features are limited and it is more effective to assure that you get the best exposure when taking the shot.

The amount of light on the image sensor, or exposure, is determined by the opening/closing of the aperture, the length of time that the shutter is open, and the amount of light present. For the purposes of this article, the discussion will be limited to working with and enhancing the light present for the shot.

When the light in a situation is not sufficient or when you want to create a different effect with highlights and shadows, an internal flash or external light source can be used. The happy news for the photography novice is that digital cameras have an auto flash feature in which the camera decides when lighting is insufficient and will activate the flash automatically.

One of the most important things to remember about using flash photography for the novice is that all cameras have a flash range. Beyond that range, generally no more than 14 to 15 feet, the flash is not effective. Flash is most often used when shooting indoors where there is generally less light.

One of the pitfalls of using flash when photographing people and animals however is the infamous "red eye" effect which is created when the light bounces off of the back of the retina of the subject. This can be reduced by having subjects avoid looking directly into the camera or using the "red eye reduction" mode. This mode simply emits a tiny flash prior to taking the picture to help the pupil contract prior to the full flash.

Glare is another common problem encountered when using flash photography but can easily be eliminated by being sure not to point the camera directly into any shiny object such as a mirror or glass. Most digital cameras allow the user to have control of the flash function giving them the ability to disable it for use in situations where flash is not allowed or the user is striving to achieve a particular look in the picture. It also allows the user to set the flash so that it is always on, allowing the flash to be used even when the camera senses adequate lighting.

Flash can be used to deal with some lighting related problems outdoors as well. Sunlight can create shadows and cause the subject to appear dark and difficult to discern with the brighter, sunlit area around them. One option is to pose your subject in the shade. Taking photographs in the shade often provides images with better/truer color definition, no shadows, and subjects free from squinting.

When in the sunlight, use of the flash can be particularly helpful in balancing the light and reducing shadows. The fill-flash mode can be useful in any situation where the subject will be darker than the surrounding background whether they are shaded by a hat, a tree, or simply their own facial features. However, fill-flash mode should be used only when the subject is within 6 feet. Beyond this distance full power mode will be necessary.

Use of an external or auxiliary flash can give the user the control necessary to adjust lighting and create special effects. Just as the intensity of a light source influences the exposure in a picture, the direction of the light source can change an image through shadows and highlights. A flash can be attached to a camera with either a "cold shoe" or a "hot shoe". A cold shoe is merely a plastic shoe that allows the flash to be physically attached to the camera but does not have any contacts that allow the camera to communicate or coordinate the flash activity. With a hot shoe, users can attach a flash sync cord, allowing them to move the flash away from the camera and choose the direction of the lighting. In addition, a hot shoe attachment allows the flash to be controlled by the camera's flash settings. With the external flash, there are various modes to control the flash function.

&bull The TTL setting allows the camera and flash to determine the best exposure based upon the focal length of the lens. This is possible when the camera and the flash are of the same brand.

&bull The Stroboscopic setting can produce multiple flashes within a single exposure to create special effects.

&bull The Manual setting allows the user to set the flash for full, half, or quarter power.

&bull The Auto setting allows the flash to determine the best exposure independently. This is used most often when the camera and flash are not of the same brand.

There are two primary types of lighting used in photography. A hard light is created from a single, bright source of light and it produces shadows, highlights and pronounced contrast in the resulting image. Soft light on the other hand is very diffuse, making highlights and shadows more subtle.

Hard light is preferable when detail and distinct color is desired, but soft light is best for a softer image. Light from a single source can be diffused in a number of ways. The flash can be covered with a thin material such as tissue or wax paper or it can be bounced off of another surface, such as the ceiling or a wall, rather than being shown directly onto the subject. Bouncing the light is obviously not effective outdoors and the distance of the reflecting structure should be no more than 6-8 feet. The color of the surface reflecting the light must also be considered. Any color on the surface is generally reflected onto the subject. For this reason, white is generally preferred although professionals use black to absorb light and darken shadows and shiny materials are used to harden the light.

As mentioned previously, the direction of lighting can also greatly influence the characteristics of a photograph. The use of an external flash gives the user the option of moving the light source in relation to the subject.

Front lighting is the most common. When wanting to emphasize the detail of the subject, front lighting is the best choice. However, it can create a rather harsh image with shadows in the background, muted colors in the foreground, and red eye. The use of fill flash and red eye reduction when using front lighting can help to alleviate some of the negative effects, while diffusing the light can reduce harshness.

Back lighting can produce a very dramatic photograph but, if too bright, can cause the subject to appear only as a silhouette unless the object is transparent. Reducing the brightness of the light source and using fill flash to brighten the shadowed areas can improve the quality of a picture with back lighting. Providing lighting from an angle rather than directly from the front or back can be beneficial in either of these lighting situations.

Lighting can also be directed from the side, the top, and from under the subject. Side lighting gives the user the most options as far as angle and the ability to create a wide variety of effects. Side lighting is optimal for creating texture and a sense of depth to a photograph.

For the novice photographer, experimentation is key. Whether diffusing light for softer images, using fill flash outdoors to eliminate shadows, or altering the direction of lighting to create special effects, creating unique, quality images requires practice.