Viewfinders, like digital camera LCD monitors, are used to compose and frame a scene. Viewfinders serve another important purpose. While looking through the viewfinder, you can steady the camera by bracing it against your face,  making the camera less prone shake.

If your digital camera has a viewfinder, it will be one of two types:

Optical viewfinder

The Optical Viewfinder is the most common one found on digital cameras. Optical Viewfinders work well in both bright and low lighting conditions. It compact digital cameras, the optical viewfinder shows only about 75-90% of what the camera lens actually sees, not the total area of a shot. When looking through the eyepiece, there is a center auto focus bracket and parallax correction line at the top. Use the parallax correction line when taking close-up shots.

Optical viewfinders on DSLRs are larger, brighter and show all or almost all of the scene. Some DSLR viewfinders also display shooting information such as shutter speed and aperture.

Electronic Viewfinder (EVF)

An Electronic Viewfinder is a small LCD. The size on most digital cameras manufactured during the last few years is between 2″ - 3.” While not quite as clear an an optical viewfinder, a LCD is more accurate than most optical viewfinders in that it shows the total area of the scene you are photographing.

An electronic viewfinder also displays key camera settings. The advantage is that you don’t have to take your eye away from the camera to look at the LCD screen for settings and accurate framing.

And electronic viewfinder has two disadvantages: it consumes battery power and it is usually not as bright and clear as an optical viewfinder.