If you’ve just started using the manual mode on your camera, metering can leave you a little confused. Most cameras have 3 metering modes – the matrix or averaging mode, the center weighted mode and the spot meter mode. Lets have a quick look at each…
In this mode, the camera takes into account multiple areas within the composition, and gives you an average reading based on these. So, you can do away with confusion when shooting high contrast subjects. The matrix mode is also an advantage when you do not have a lot of time on your hands to think about what part of the subject would give you an accurate reading.
The Center Weighted Mode:
This mode gives a priority to the center of your viewfinder, since in most cases people tend to center the subject (which by the way is not by any yardstick a golden rule of composition). Understandably, the center weighted mode tends to work well for subjects such as portraits where the model is usually centered. This is a somewhat more accurate metering mode compared to the Matrix.
The Spot Meter:
The Spot metering mode is the most accurate of all, but can also throw your exposure settings off unless you use it carefully. The spot meter employs just one spot within the composition, to give you a reading. In some camera models, this spot can be moved within the viewfinder. If it is stationary in the center, you need to center the area of the viewfinder that you want your reading from, take the reading and re-compose. While this might take a little more time to use than the other 2 modes, the spot meter is undoubtedly the choice of the professional.
Take a look at the accompanying image. This effect could only be achieved with a spot meter. The averaging meter would have accounted for the shadow areas as well, and given you an exposure where the face of the person may have been burnt out. The center weighted could have worked, provided the reading was taken from the face of the person. However, the center weighted mode would have also accounted for the shadow areas, but not as much as the matrix mode. A spot reading off the face has given us a very accurate reading so as to create a perfect exposure off the skin, and darken the rest of the shadow area. Look for high contrast scenes such as this, and try spot readings off various areas of the composition – you’d be surprised at the different readings you get!