November 22, 2010, 11:21 AM — Viewfinders are what photographers rely on to accurately compose a pictures. There are different kinds of viewfinders, and it's important to understand the pros and cons of each before buying a camera.
Cameras can have an LCD screen with Live View, an optical viewfinder, an electronic viewfinder, or a combination of these. For example, many DSLRs cameras now come with LCD screens with Live View, in addition to an optical or electronic eye-level viewfinder. Many point-and-shoots only have an LCD screen.
The electronic viewfinder technology has come a long way in the past few years and some DSLRs are using them instead of the more traditional optical viewfinders. Here is a look at each type of eye-level viewfinder and what they have to offer.
Found on DSLR cameras, a pentaprisim optical viewfinder (OVF) allows a photographer to compose a shot while seeing exactly what the lens sees by looking through the lens (TTL). This optical viewfinder works by using a system of mirrors and prisms, like a periscope, to bounce the image up to the viewfinder and the eye. This is the preferred viewfinder for many pro-photographers.
The optical viewfinders on point-and-shoot cameras are different in that they don't show you exactly what the lens sees; these are called pentamirror optical viewfinders and they look through a separate hole above the lens and show a slightly different view from the final image.
Pros: The advantages of the OVF are that the photographer sees a scene with no time lag, no resolution limits, and with all the clarity the lens and the human eye can produce. Sports shooters rely on this system to see action immediately and anticipate the kind of timing necessary to capture the right moment. OVFs also save battery since looking through them doesn't require any charge, and the photographer can take time to compose a shot before turning the camera on. And anyone who has tried to use an LCD screen in bright sunlight can appreciate that eye-level viewfinders aren't affected by reflections.
Cons: Optical viewfinders usually show a smaller portion of a frame than what the final image will actually include, and they can feel a bit like looking through a tunnel. Camera manufacturers will list the percentage of the frame a viewfinder covers in a product's specs. For example, the Nikon D3100's viewfinder shows 95% of what the sensor captures.