For a generation that has been raised in front of a television or computer screen, it may seem reasonable and normal to use those little LCD screens, on the back of digital cameras, as view finders. Indeed, many of the smaller digital cameras no longer provide a conventional, "optical" view finder (you know, the kind that you must place up against your eye when in use). But there are many reasons why the use of LCD screens as view finders results in fewer good images than are otherwise possible; here are just seven of those.
They're hard to read in bright light
Most of us have learned a basic general rule about keeping the sun to your back when making photographs. With the sun coming over your shoulder, it can't help but strike the LCD screen, thus washing out detail so much that you're only guessing at what you'll see in the final photo.
You can't focus your attention on what you should
With the camera held out at arm's length, so that your eye can focus on the LCD screen, your peripheral vision will encompass a great deal more than what's in the intended image. That distraction results in less-than-optimal composition; you certainly can't really make out your subject's facial expressions on that tiny screen, two feet away from your eyes.
Uncovered optical viewfinders can seriously degrade image quality
Some cameras have optical viewfinders that actually look through the lens when composing the image (particularly SLRs). In such cases, failure to cover the optical viewfinder (with your face, or a small shield of some sort) allows bright light to enter the camera from the rear while the image is being exposed, which will seriously wash out all or part of an image. So using the LCD to compose a SLR can be especially risky.
Cameras held against the face are steadier than those held out at arm's length
When using an optical viewfinder, the photographer usually minimizes movement, which would be introduced when extending the camera to arm's length when using the LCD as a viewfinder. Unintended movement generally results in degraded image quality.
LCD screens drain batteries
LCD screens are the camera's major user of battery power. Turning them off when not needed will permit you to make more photographs between battery changes, which often happens at the most inopportune times. Most digital cameras have a menu option for that; if your camera has an optical viewfinder, check your manual to find out how to turn off the power-hogging screen, and do it.
Tracking moving subjects while using the screen is difficult, at best
Every LCD screen has a refresh rate (i.e., the number of times per second that the picture on the screen is changed). Slow refresh rates are clearly apparent when you pan (swing a camera in an arc) while following action. Even under the best of conditions, the image on the screen will blur if you move the camera rapidly. Clearly, that's undesirable! When recently in a group of photographers observing cheetah training, the author was the only one using an optical viewfinder, and the only one that ended up with a satisfactory image (see attachment below).
Protection in the rain
Photographers often wear caps or hats with brims expending over their faces, so when a camera is held against the face (as in while using an optical viewfinder), it is partially shielded from light rain or snow. If one holds a point-and-shoot digital out at arm's length, it's obviously exposed to the elements. And let me assure you that most of those small digitals aren't at all waterproof.
In Conclusion
The use of an optical viewfinder will significantly enhance your ability to make the best possible photographs, while also conserving limited battery power. Your present camera may not feature an optical viewfinder, but look for one when shopping for a replacement.
