Metering modes The exposure meter in digital cameras is a powerful and flexible device. As a rule there are three modes of measurement, but they are not available in “AUTO” mode.
(Screenshot – metering settings)
Multipoint or Multisegment – light measurement is taken from many points in a shot, then an according data array common exposure can be calculated with great precision for almost all conditions. The number of points measured varies in different cameras from 64 to 512.
Central Weighted – almost the same, but the calculated data from the central zone of view have a higher priority. It is reasonable, because usually that’s where the main subject is.
“Spot” – a special metering mode. In this case measurement is taken from a very small central point. No other part matters. This mode is not used very often, when you are shooting an object with a very dark or a very glaring background. Mostly it’s indicated by a small ring the in centre of viewfinder.
Pay attention to the spot metering, it is very sensitive and you should to point the camera to an area of the object with “typical” illumination. But what do you do, when the place is offset from the middle of the viewfinder? For such cases there’s a special feature: “Focus Lock”.
You should point to the object for metering and half-press the button, then return the camera to the original position to compose the scene and, finally, shoot it. The camera saves the settings while the button is half-pressed and uses them for your shot.
Exposure modes
First of all you have to the switch on your camera for selecting the different modes. As a rule, it looks like a rotating head on the top of the camera or on the back. The definitions used for exposure modes are standard.
(photo)
In full-automatic mode (“AUTO”) most settings are off and you can’t adjust them manually. This is the usual mode for beginners.
For learning and testing of some ideas from this book it is better to switch to “P” mode. There you get more freedom for camera adjustment, but the shutter setting speed and aperture opening is still automatic. This mode is great for when you are starting really studying photography and your camera’s capabilities, because it can protect you from drastic technical mistakes, but you will be able to get a feel for your camera.
For most advanced users almost all models provides half-auto modes with priority of shutter (“S”) or aperture (“A”). You set the “priority” value manually, and second one is adjusted by the microcontroller.
In manual (“M”) mode you can set both parameters, and the camera only shows you the result. This is usually necessary when shooting at night, with a very slow shutter time – more then 1s.
As mentioned earlier, some of the older entry-level digital cameras only have automatic mode, and the features are very limited. Such models have not really been produced for the last 3-4 years, and in modern cameras at least half-automatic modes are present.
