Camera Metering Modes Explained: Which to Use for Portrait Photography

What Metering Modes Do

Your camera's metering system measures the brightness of the scene to determine the correct exposure. Different metering modes measure different areas of the frame, and choosing the wrong one for your situation leads to consistently incorrect exposures — especially when shooting portraits against non-neutral backgrounds.

The Four Main Metering Modes

1. Evaluative / Matrix Metering

Called Evaluative on Canon cameras and Matrix on Nikon, this mode analyzes the entire frame and uses a complex algorithm to calculate an overall exposure reading. It considers brightness across hundreds of zones, weighs the active focus point, and compares the scene to a database of known lighting patterns.

Evaluative metering is the default on most cameras and the right choice for most situations. In evenly lit scenes — outdoors in open shade, overcast days, studio environments — it produces accurate exposures with no adjustment needed. This is where most photographers should start.

2. Center-Weighted Metering

Center-weighted metering measures the full frame but gives heavier weight to the center area, typically the central 60-80% of the image. It's a compromise between reading the whole scene and reading only the subject.

Useful when your subject is centered in the frame and the background exposure matters to you, but you want the subject's brightness to dominate the reading. It's less susceptible to extreme backgrounds than evaluative metering but less precise than spot metering.

3. Spot Metering

Spot metering reads only a small area of the frame — typically 1-5% — centered on the active focus point. It ignores the rest of the scene entirely and bases the exposure on that one small zone.

This is the most powerful and most situationally specific metering mode. When a subject is backlit against a bright sky or bright window, evaluative metering will see the bright background and underexpose the subject's face. Spot metering placed on the face ignores the bright background and exposes correctly for the skin.

4. Partial Metering

Partial metering is a Canon-specific mode that works similarly to spot metering but covers a larger reading area — approximately 10-15% of the frame around the center. It's a middle ground between center-weighted and spot metering, useful when spot metering feels too precise for the situation but center-weighted is too influenced by the background.

When to Switch from Evaluative to Spot Metering

Switch to spot metering when:

• Your subject is backlit against a bright sky, bright window, or any light source behind them
• The scene has high contrast between the subject and background
• The subject is against a very bright background (white wall, snow, beach sand) or very dark background (night scenes, dark studio backdrop)

In these situations, evaluative metering averages the bright background into the reading and underexposes the subject's face. Spot metering eliminates the background from the calculation entirely.

How to Use Spot Metering Correctly

When using spot metering for portraits:

1. Set your AF point to single point
2. Place the spot on the area of skin you want correctly exposed — typically the face or forehead
3. Half-press the shutter to take the reading
4. If you need to recompose, use the AE-L button to lock the exposure reading before moving the camera

The AE-L Button (Exposure Lock)

The AE-L or AE-L/AF-L button on your camera locks the exposure reading independently of where the camera is pointed. This is essential when using spot metering and recomposing — take the spot reading off the subject's skin, press AE-L to lock it, then reframe your shot and fire. The exposure stays locked to the skin reading regardless of what else is in the frame.