So why are viewfinders so important if cameras come with nice big screens? Just take a typical point and shoot camera out in bright sunlight. Good luck accurately framing or focusing your shot. On higher end cameras, viewfinders offer the ability to fine tune shots with manual focus, and provide shooting information. There are some important differences between optical and electronic viewfinders, and knowing the pros and cons of each type may help in a decision of what type of camera to purchase, especially if you are considering an interchangeable lens camera.
Optical Viewfinders:
On some higher end point and shoot cameras, like the Nikon P7000 or the Canon G12, there is an optical viewfinder in addition to the LCD screen. This type of viewfinder is essentially a small window near the lens that you can use for framing. Unfortunately, since it is near the lens, but not the lens, what you see is not exactly what you get. It is an approximation meant to help compose photos, but be careful to review the images to make sure you got the shot you were hoping for.
DSLR cameras offer a far better type of optical viewfinder, called a pentaprism, which uses a mirror to allow the user to essentially see through the lens. This is especially useful since you are able to clearly see everything the lens sees, and it makes things like manual focus, and small depth of field changes easy to see. In addition, the viewfinder will display shooting data such as f-stop and shutter speed, and give some other exposure related information. The coverage on this type of viewfinder is usually close to 100%, so framing and composing shots is far more accurate than with the type of viewfinder found on point and shoot cameras. Using optical viewfinders also makes the camera more energy efficient, so battery life is extended.
Electronic Viewfinders:
There are different types of electronic viewfinders as well. Many non-interchangeable lens cameras with a lot of zoom (sometimes called "superzooms"), like the Nikon P100, the Canon SX30IS, or the Panasonic FZ100, use electronic viewfinders that are essentially small LCD displays inside the viewfinder. This type of viewfinder is nice because it can display lots of information, and does provide an exact view of what the image will be, as opposed to some optical viewfinders. Not all electronic viewfinders are created equal however, and resolutions can vary significantly. If finding a camera with a built in electronic viewfinder is important, you should definitely try out different models to see firsthand. Some are remarkably sharp, while others can look very pixilated.
On interchangeable lens cameras using the micro four-thirds system like the Olympus E-PL1 or the Panasonic GF1, the electronic viewfinders attach on top of the camera, since the cameras themselves are so compact they can't house an in-camera viewfinder. These viewfinders also vary in resolution, so again make sure you check out each model if the viewfinder is something you think you will need or want to use. These type of viewfinders can be great for displaying lots of shooting information, and often beat optical viewfinders in low light. The resolution is limited however, and remember, more power consumption means shorter battery life.
The important thing to remember is that each type has it's strengths and weaknesses. Depending on the type of camera you are looking into, the size you want, and your shooting style, one may be much better suited for your use than the other. It really will depend on the user. So it is important to understand what you are getting if you are looking for a camera with a viewfinder. The easiest way to do this of course, is to come into your nearest Penn Camera and see the differences for yourself. Until you see for yourself, don't make any decisions. For some people the viewfinder can truly make or break the camera.
