The internal light meter in your camera is instrumental for telling you if a scene will be over or under-exposed if you’re shooting in manual mode. And when shooting in something like program mode, aperture priority or shutter priority, the metering modes become even more important because the camera makes the final decision for the shot taken.
Basically, the meter will take a region of the scene in accordance with the selected metering mode and try to average it out to 18% gray. So if you have a very dark subject in an otherwise very bright scene, and are on a metering mode that takes in consideration the whole scene, the dark subject will most likely be under-exposed because the meter took too much of the rest of the scene in consideration.
The Different Metering Modes
In this post we’ll cover the different metering modes you’ll find in modern DSLR and mirrorless cameras.
The names used and available metering modes will differ a bit depending on your camera brand. For example, with Nikon cameras you’ll have 3 options:
- Center-weighted average
- Spot metering
With Canon, you’ll have 4 options:
- Spot metering
Matrix and evaluative follow essentially the same principles, so they can be lumped together, but partial metering is an option that you get with Canon and won’t get with Nikon.
Let’s now break down the 4 metering modes. I’ve included what the icons for the metering modes usually look like:
Evaluative metering (aka matrix metering) is often the default for cameras and will try to average out the whole scene. This metering mode can work well with landscape photography or otherwise evenly distributed tones, but will often fall short when you’re photographing subjects that are brighter or darker than the rest of the scene.
With spot metering, the meter only takes a single spot from the scene into consideration. Most professional DSLR or mirrorless cameras will spot meter according to the where the autofocus point is set in your scene. This is very practical because it allows to meter wherever your focusing, which is won’t necessarily be at the center of the scene, depending on your composition.
Canon cameras also have a partial metering option, which is really similar to spot metering, but with a larger spot area taken into consideration.
Center-Weighted Average Metering
With center-weighted average metering, the whole scene is taken into consideration, but a priority is given to what’s at the center of the metered scene.
Personally, I usually like to set my meter to a mode of spot or center-weighted average, which both work well with portraits. Otherwise, I’ll use evaluative/matrix metering only on occasion when I take landscape photographs or for simple snapshots while walking about.
And if, in spite of properly setting the metering mode, you find your photos are consistently over or under-exposed for certain scenes, you’ll want to play with your camera’s exposure compensation, which I’ll cover in a future post.