Metering In Photography.
Metering is a process which involves the camera taking a light level reading from the scene and selecting the appropriate combination of aperture and shutter speed to set the required exposure value.
Different metering modes allow you the photographer to select the most suitable one for the specific lighting conditions.
They can be changed manually by use of the exposure compensation meter as required; here are some of the selections you will come across.
Here a metering is taken from the whole scene first, then the central spot.
The result is the average reading, but with extra weight given to the central part.
Some cameras allow you to change the amount of weight given to the central area usually 60 – 80 per cent of the sensitivity is directed toward the central part of the image, making it a good choice for portrait photography.
Spot metering takes a reading from a very small part of the image (usually 1 – 5 per cent) it then ignores the exposure from the rest of the scene.
While this area is usually in the middle of the scene, with some cameras the user can select a different part of the image from which to take a reading.
Spot metering is a good choice for high contrast and backlit scenes but care should be taken aiming for an area that will form the mid-tone part of the final image.
Was first introduced by Nikon.
Zone metering takes readings from several different (areas – or zones) within the scene, to produce a calculated average.
The number of zones used varies dramatically from one camera to another, but overall the end result is usually an average of them all, useful for general scenes with low contrast.
There are other types of metering but they tend to be variations of these above mentioned types.
Having different metering modes available becomes useful when you start progressing in your photography.