This article explains the four main exposure metering methods in photography: multi-segment metering, center-weighted metering, average metering, and spot metering. The camera measures light based on an 18% gray reference value, which can lead to incorrect exposures in extremely bright or dark scenes. For beginners, multi-segment metering is recommended, while spot metering offers more control in challenging lighting conditions. Exposure compensation is often necessary.
Category: Photography Basics > 3. Exposure & Camera Settings Article ID: 3.6 Created: May 2026
Key Points at a Glance
- Before the camera can calculate an exposure, it must measure the light in the scene – this is done using different metering methods
- The four main methods are: multi-segment metering, center-weighted metering, average metering, and spot metering
- The camera always assumes an 18% gray reference – in very bright or dark scenes, this can lead to incorrect exposures
Explanation
Why Does the Camera Need Exposure Metering?
In order for the camera to automatically set aperture, shutter speed, and ISO, it must first determine the light value of the scene. To do this, it analyzes the light in the frame – depending on the selected metering method, this is done in different ways.
Important: The camera assumes a reference value of 18% gray – the average reflectance value of natural scenes. If a scene deviates significantly from this (e.g., snow, white wedding dress, black background), the camera will calculate the exposure incorrectly – and exposure compensation will be necessary.
The Four Metering Methods
1. Average Metering
- Measures brightness evenly across the entire image area and calculates the average
- Simple and easy to understand – corrections can be estimated well
- Problematic in scenes with strong brightness differences (e.g., backlighting, shadows next to sunlight)
2. Center-Weighted Metering
- An advancement of average metering: the center of the image is weighted more heavily than the edges
- Well suited when the main subject is in the center of the frame
- Fails when the subject is off-center or there are strong contrasts
3. Multi-Segment Metering (Matrix Metering)
- The camera divides the image into many small segments, measures each area individually, and weights the segments according to a manufacturer-specific algorithm
- Most error-tolerant method – recognizes typical subjects (landscape, portrait, backlight) and adjusts metering accordingly
- Standard on modern cameras and recommended for everyday photography
- Downside: The behavior of the algorithm is hard to understand; corrections are difficult to estimate
4. Spot Metering
- Measures brightness only at a very small point in the image (usually 1–5% of the frame)
- Maximum control: the photographer decides exactly which area should be correctly exposed
- Ideal in difficult lighting conditions: stage lighting, backlight, moon shots
- Requires experience – incorrect placement of the metering spot directly leads to incorrect exposure
- Often not available on basic cameras
Metering Methods Compared
| Method | Metering Area | Error Tolerance | Controllability | Typical Use |
|---|---|---|---|---|
| Average Metering | Entire image evenly | Low | High | Simple, evenly lit scenes |
| Center-Weighted Metering | Focus on center | Medium | Medium | Portraits, center-focused subjects |
| Multi-Segment Metering | Many segments, weighted | High | Low | Everyday photography, standard |
| Spot Metering | Single point | Very low | Very high | Stage, backlight, special shots |
The 18% Gray Effect in Practice
Typical situations where automatic exposure metering fails:
- Snow or white beach: The camera sees a lot of brightness, interprets it as "too bright" and underexposes → gray snow instead of white. Solution: Exposure compensation +1 to +2 EV.
- Dark background (e.g., stage): The camera exposes the dark background to 18% gray → main subject (performer) becomes overexposed. Solution: Spot metering on the main subject or exposure compensation −1 to −2 EV.
- Backlight: Bright light from behind overwhelms the metering → subject appears too dark (silhouette). Solution: Exposure compensation or fill flash.
Practical Tip
For beginners: set multi-segment metering as the standard and adjust with exposure compensation (→ Article 3.8) if there are problems. Those who want to take control should try spot metering – preferably first with a static scene outdoors to get a feel for how the camera reacts to different metering points.