Digital Photo Light Settings

Digital cameras have two settings—ISO and white balance—that allow you to take best advantage of the lighting conditions in the scenes you’re shooting.

The ISO setting controls the sensitivity of your digital camera’s light sensor. The ISO setting range on entry-level digital cameras is usually 50–800.

Photos taken at higher ISO settings look grainier than photos taken at lower ISO settings. The grainy appearance of photos taken at high ISO settings results from digital noise, errant colored pixels that the sensor picks up due to its heightened sensitivity. To mitigate this problem when shooting in low light, take several shots at varying ISOs and use the one with the best exposure and least noise. The image above on the right shows the effect of digital noise.

Light from different sources (such as the sun, a tungsten bulb, or a fluorescent bulb) is made up of different levels of red, green, and blue light, creating different qualities of light. The human eye compensates for the various levels of red, green, and blue contained in different types of light, so what appears blue in sunlight appears blue in all types of light. But cameras don’t compensate for these differences, and objects that look white to the camera in sunlight might look blue under fluorescent light.

To correct this problem, digital cameras include a white balance setting, which allows you to specify the type of light, such as sunlight or tungsten (light bulb) light, in the scene you’re shooting. The camera then uses the color white—as it should appear in that type of light—as a benchmark by which it renders the other colors in the scene. Setting your camera’s white balance properly ensures that the colors in your photos will appear accurate based on the type of light in the scene. For instance, the following two images were shot in sunlight. The image on the left has the correct white balance setting, but the image on the right has the white balance set for tungsten light, producing a blue tint.

Most digital cameras have these white balance settings:

If more than one light source is present, as in a room with both tungsten and fluorescent lights, try taking the photo more than once with different white balance settings.

If you’re shooting in low-light conditions, such as outdoors at night or in a dark room, you’ll need to use either a tripod or a flash.

A tripod is a three-legged device that connects to the bottom of the camera to support the camera when taking long exposures in daylight or any exposure without a flash in low-light conditions. Some photographers choose to use a tripod in almost all light conditions to reduce the effect of camera shake, the blur that can result from your hand’s natural movement when you press the shutter.

Photographers use a tripod in tandem with a remote release, a device that lets you fire the shutter remotely. You can buy a basic tripod for as little as $20 and a remote release for about $30–50. If your camera doesn’t take a remote release, use the camera’s timer function to fire the shutter automatically when using a tripod.

A flash creates a burst of light to illuminate low-light scenes. Photo­graphers use a flash when shooting in dark rooms or outdoors at night. You might prefer to use a tripod rather than a flash, since a flash sometimes gives a photo a washed-out look. Nearly all digital cameras include a built-in flash. Midsize digital cameras and high-tech digital SLRs (see the Quamut guide to Buying a Digital Camera) also accept external flashes, which mount on top of the camera.