Working with the LCD Viewfinder on a Digital Camera

You usually find a color LCD (liquid crystal display) screen on the back of the camera, which you can use to preview and review your electronic images. The LCD, measuring from 1.5 to 2.5 inches diagonally, shows an electronic image of the scene as viewed by the sensor. This setup has its good and bad sides:

• Great: You can view more or less the exact image that will be captured.

• Not so great: The LCD display is likely to be difficult to view, washed out by surrounding light, and so small that it doesn't really show what you need to see. Moreover, the backlit LCD display eats up battery power. Luckily, some digital cameras let you specify that the LCD is turned on only when composing a picture or only for a few seconds after a picture is taken (so that you can quickly review the shot).

Although often not usable in bright daylight, LCDs, such as the one shown in Figure 1, are better in more dimly lit conditions. Some third parties offer LCD hoods that fit over the back panel of the camera to shield the LCD from direct illumination. If you mount your camera on a tripod and make sure all the light is directed on your subject, an LCD is entirely practical for framing, focusing, and evaluating a digital image (even outdoors, if you use one of those protective hoods).

As you shop for a digital camera, check out the LCD display under a variety of conditions to make sure it passes muster. Here are some things to look for:

• Accurate rendition: Some LCDs don't let you evaluate just how good (or bad) your picture is because they provide an image that's brighter or has more muted colors than the actual digital picture. You don't want to reshoot a picture because you think it looked bad on the LCD. Or worse, make a manual exposure or other adjustment to correct a defect that appears only on the LCD and not in the finished photo.

• Accurate viewpoint: Believe it or not, even though an LCD viewfinder's display is derived from the same sensor used to make the exposure, the LCD might not display 100 percent of the sensor's view. Instead, it might trim a little off the sides, top, and bottom, and show you 80–90 percent of the actual picture. That's not good when you're carefully composing a photo to make the most of your pixels, particularly with lower-resolution cameras that don't have pixels to spare.

• Brightness controls: Many cameras include a brightness control that allows increasing the brightness of the LCD to make it easier to view in full sunlight or decreasing the brightness indoors to use less battery juice.

• Display rate: Some digital cameras update their LCD images more efficiently, so the view is smooth even when the camera or your subject is moving. Others offer up blurry images or ghost trails that make it difficult to view images in motion.

• Realtime corrections: Some cameras have live histograms — graphs that show the distribution of the tones in the image — that can be viewed on the LCD and used to correct exposure manually while you shoot.

• Resolution and size: Ultracompact digital cameras often have tiny LCD displays, on the order of 1 1/2 inches (measured diagonally), and others have more generous 2-inch LCDs. The size of the LCD and the number of pixels it contains will partially determine how easy it is to preview your image.

• Swivel mount: The LCD doesn't have to remain fixed rigidly to the back of the camera. Some swivel and rotate, allowing you to point the camera in one direction and move the LCD so that you can easily view it at an angle. (Alternatively, the part of the camera with the lens can swivel while the part with the LCD remains in place.)

• Vanishing images: What happens when you press the shutter release? Does the image instantly freeze as soon as you start to press the button but before you actually take the picture? If so, what you saw might not be what you get because your subject matter might have changed in the time between the initial press and the actual photo. Or, does the LCD go completely blank, leaving you with no clue about what you're shooting? Ideally, the LCD should display a real-time image right up until the instant before the picture is taken.