Before the light meters, the only way we could get a proper exposure is by a lucky guess. Before meters, when a photographer wanted to determine what the correct exposure was, he/she might say, "Well, this room is fairly well lit, with no windows. I am using a tripod, so I guess that I should set the camera to f/2.8 at 1/30 of a second. Well, no, maybe I should make it one stop higher...". Exposure was a difficult thing then! So, when light meters were invented, it saved many photographers' lives.

The modern light meter is a very sophisticated mechanism. The simplest of light meters consist of a light-sensitive cell which when it reacts to light, gives the user a TTL(through-the-lens) reading made of three symbols (- O +, meaning underexposure, proper exposure, and overexposure). These meters first appeared in such cameras in the 1970s, such as the Nikon F3. These meters, though simple, really helped the photographer in setting the exposure. A few new cameras, such as the Ricoh KR-5, still use put this type of meter in their cameras. This type of metering is called center-weighted metering.

Toady's meters are many times more advanced than they were 20 years ago. Meters today are controlled by a microprocessor, and are fully electronic. Some meters are so sophisticated that they can adjust shutter speeds and f-stops automatically(this is called auto-exposure), so that you can pay more attention to such things as composition and lighting.

Invented in the late 80's, autofocusing is, well, focusing the lens automatically. A camera's autofocusing system determines what should be in focus by emitting ultrasonic sound waves or infrared light beams. Once they bounce off an object, they return to the camera, and determine what the lens should be focused at, and the lens is then adjusted by a motor in the camera or lens.

Oh, yes, if you are primarily going to be using autofocus for most of your work, you should consider a Canon EOS camera. Canon produces the most sophisticated and fastest autofocusing system in the world. This is because that in their USM (ultrasonic motor) lenses, there is a ring motor, which makes almost no noise when focusing, and are also extremely fast. The only drawback is that these lenses can get to be very expensive.

Nope. At least not always. Even though automated exposure systems are very sophisticated, you should use them when necessary. This is because in many cases, the autoexposure system may be confused when there is difficult lighting, and make a wrong decision. Autoexposure and autofocus are most suitable when you are shooting sports, candids, or any fast-moving object, when you don't have time to think about exposure. You will find that when you are shooting scenery, it is a good idea to take along a tripod and adjust the stops, shutter, and focus manually (I'm pretty sure that those rocks and trees won't walk away anyway; you will have plenty of time).

Well, yet another innovation in photography saved us from losing a great picture! Next, I will explain to you about the wide variety of picture-takeing that is available to you.