Tips for Using Exposure Metering Modes

The metering modes in DSLRs measure the amount of external light in a scene, and then apply the best exposure values according to the metering mode selected. Automatic exposure is a feature on all DSLRs, but you can select from different metering modes. Depending on the camera manufacturer and model, there will be either three or four metering modes to select from, as I've listed here.

Use these tips for understanding and using exposure metering modes more efficiently!

Evaluative or Matrix Metering

This is the most complex mode, but it offers the best exposure for most scenes. Essentially, the camera divides the scene into a matrix of metering zones, and takes individual readings for each section. An evaluative meter reading then is diagnosed, and an average metering for the whole scene is given.

Pros

1. Easy to use
2. Good for landscapes and group photographs

Cons

1. Not great for scenes with strong light and lots of shadows -- parts of the photo will end up over or under exposed.
2. Will struggle to meter for a small subject.

Center-Weighted Average Metering

This is the most common metering mode, and the default option for cameras that don't have different metering modes. This mode averages the exposure for the entire scene, but gives extra weight to the center area.

Pros

1. Ideal for photographing people or objects in the center of a landscape or scene as it will meter for them over background areas.
2. Good for portraits as it exposes for the subject and not the background.

Cons

1. No good if your subject or object isn't in the center of the frame.
2. Not great for head-and-shoulder shots that fill the frame as it will meter primarily for the center of the face and outer areas could be over or under exposed.

Spot or Partial Metering

Some DSLRs have both of these, some have only one, and some have neither of them. These metering modes are used for very specific purposes. Spot metering meters for the center 5% of the image, while partial metering meters for the center 15% of the image. The rest of the exposure is ignored.

Pros

1. Great for macro and still life work, as it allows for very precise metering on small objects.
2. Good for photographs that are very brightly backlit to help avoid silhouetting of the subject.

Cons

1. Requires extremely careful use and is time consuming. Patience is required to get the ideal shot!
2. Limited uses, and it's only really required for specialist photography.