Every time you raise your camera, the metering system is working in the background making a judgment call about how bright your image should be. Get that judgment wrong — or let the camera get it wrong — and no amount of composition or technique saves the shot. Overexposed highlights, underexposed subjects against bright skies, faces going dark in backlit situations: these are all metering failures, and they happen to photographers who never thought to question the default.

This guide covers what metering modes are, how each one works, and when to reach for each one in real shooting situations. It also covers the 18% grey concept that underpins all of them — because once you understand that, the behavior of every metering mode makes immediate sense.

We default to Spot metering for most controlled shooting and Evaluative for fast documentary work. The reasoning behind that is in here.

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What a metering mode actually does

A metering mode defines which portion of your frame the camera samples when calculating exposure. The camera reads the light in that area, runs it through its exposure algorithm, and produces a shutter speed, aperture, or ISO recommendation depending on which shooting mode you’re in. Change the metering mode and you change which part of the scene the camera is basing that recommendation on — which changes the result, sometimes dramatically.

The underlying goal of every metering mode is the same: find a correct exposure. They differ only in where they look to gather that information.

The 18% grey concept: why cameras meter the way they do

To understand metering, you need to understand 18% grey. Camera meters don’t actually know what a correct exposure is in any absolute sense — they can’t distinguish between a white wall and a black wall. What they do is assume that whatever they’re measuring should, on average, render as a medium tone: 18% grey, the midpoint between pure black and pure white.

In practice, this means the camera takes the brightest and darkest elements it’s sampling, finds the midpoint between them, and exposes to render that midpoint as a medium grey. In a scene with balanced tones — a landscape with a mix of sky, foliage, and ground — this works well. The average of a well-balanced scene is close to middle grey, and the camera’s guess is close to correct.

The problem arises in scenes that aren’t balanced. A subject against a bright sky, a face lit against a dark background, snow in winter sun — these scenes have an average tone that isn’t close to middle grey, and the camera’s assumption breaks down. The metering mode you choose is the tool for managing that breakdown.

Evaluative metering (Canon) / Matrix metering (Nikon) / Multi-zone metering

Evaluative or Matrix metering — different manufacturers use different names for essentially the same concept — divides the frame into zones and uses a proprietary algorithm to calculate exposure across all of them. The camera weights different zones differently, considers where the active focus point is, and applies manufacturer-specific logic to arrive at a final reading.

This is the default metering mode on most cameras and the right choice for the majority of fast-paced shooting situations. In normal lighting — outdoor daylight, evenly lit interiors, scenes without extreme contrast — Evaluative metering produces accurate exposures reliably and quickly. The camera is doing a lot of work behind the scenes and, in most cases, it gets it right.

The limitation is that the algorithm is proprietary and opaque. You don’t know exactly what the camera is weighting or why, which makes it harder to predict its behavior in unusual scenes. High-contrast situations, artistic compositions with intentionally dark or bright areas, and tricky backlit scenarios can all fool Evaluative metering in ways that are difficult to anticipate. When that happens, you’re either correcting with exposure compensation after the fact or switching to a more predictable metering mode.

How to set it on Canon (5D Mark III shown):

How to set it on Nikon (D800 shown):

Center-weighted average metering

Center-weighted metering samples the entire frame but gives significantly more weight to the center area — typically a circle covering the central 60–80% of the frame, with progressively less influence toward the edges. It’s a middle ground between the full-scene analysis of Evaluative and the surgical precision of Spot.

Center-weighted was the standard metering mode on film cameras before multi-zone metering was developed, and many photographers who came up shooting film still default to it. It’s predictable — the camera is explicitly telling you it’s prioritizing the center — which makes exposure compensation intuitive. If your subject is in the center and the edges are bright, the center weighting prevents the bright periphery from pulling the exposure down.

In our experience, center-weighted works well for environmental portraits where the subject occupies the center of the frame and you want to expose for them without completely ignoring the surroundings. It’s less useful for off-center compositions where your subject isn’t near the middle, because the meter will be influenced by whatever is centered rather than wherever your subject actually is.

Spot metering

Spot metering samples a very small area of the frame — typically 1–5% depending on the camera — and bases the entire exposure reading on that area alone. Everything outside the spot is ignored completely. On most cameras, the spot is tied to the center of the frame, though some bodies and systems allow you to link the spot to the active AF point.

Spot metering gives you the most precise control over exposure of any metering mode. Place the spot over your subject’s skin, a specific highlight you want to protect, or any particular tone in the scene, and the camera will expose to render that exact area as a medium tone. In Manual mode, this becomes a powerful tool — meter off the subject, note the reading, and set your exposure accordingly. The rest of the scene may go bright or dark, but your subject will be correctly exposed.

How to set it on Canon (5D Mark III shown):

How to set it on Nikon (D800 shown):

The precision of Spot metering is also its risk. Sample from the wrong area and the exposure is wrong in a very specific, hard-to-predict way. A small bright patch in the center of the frame will cause the camera to dramatically underexpose everything else. A small dark patch will blow out highlights across the scene. Used deliberately, this is a tool. Used carelessly, it produces more exposure errors than Evaluative.

One important note: be careful using Spot metering in semi-automatic modes like Aperture Priority. In those modes, the camera is actively adjusting shutter speed based on the meter reading — if the spot lands on a bright or dark area between frames, the exposure shifts. In Manual mode, the meter is advisory only and won’t change your settings, which is why Spot metering and Manual mode pair naturally together.

Partial metering

Partial metering is a Canon-specific mode that samples a larger area than Spot — typically around 10–15% of the frame, usually centered — but smaller than Center-weighted. It sits between Spot and Center-weighted in terms of both precision and predictability.

In practice, Partial metering is useful in the same situations as Spot metering but with a bit more forgiveness for imprecise placement. For a subject’s face that occupies a moderate portion of the center frame, Partial metering will read primarily from the face without being as sensitive to exact placement as Spot. Nikon, Sony, and Fuji don’t offer a distinct Partial mode — their Spot modes simply vary in size by body.

Which metering mode to use and when

The honest answer is that most photographers will do well with Evaluative metering as their default and Spot metering as their precision tool when Evaluative isn’t producing the result they want.

Evaluative is best when light is relatively consistent, you’re moving fast and don’t have time to meter deliberately, or the scene is well-balanced enough that the camera’s algorithm can be trusted. Wedding documentary coverage, street photography, event work — Evaluative with confident use of exposure compensation handles these situations well.

Spot metering is best in Manual mode when you need precise control over a specific subject tone. Backlit portraits where you need to expose for the face regardless of the bright background behind it. High-contrast scenes where Evaluative is clearly being fooled. Studio work where you want to meter a specific area of the scene deliberately. And for HDR photography in Manual mode, where you’re setting your median exposure based on a specific tone in the scene before bracketing above and below it.

Center-weighted sits between the two — predictable, less sensitive to where the subject is in the frame than Spot, less opaque in its logic than Evaluative. It’s a solid choice for photographers who want more control than Evaluative offers but find Spot too precise for fast shooting.

For more on how metering interacts with your shooting mode and exposure settings, see our guides on camera modes and the exposure triangle. And for a structured path through all of these camera fundamentals together, our Photography 101 Workshop covers metering, exposure, and camera controls through practical field exercises. The complete Learn Photography hub has the full progression.

Frequently asked questions about metering modes

What is the best metering mode for portraits?

For portraits with consistent, controlled light — studio work, outdoor portraits in even shade — Evaluative metering works reliably. For backlit portraits or any situation where the background is significantly brighter or darker than the subject, Spot metering in Manual mode is more reliable. Place the spot on the subject’s face, note the reading, and set your exposure accordingly. The background will take care of itself, or you can adjust flash or reflectors to bring it into the range you want.

Should I use Spot metering all the time?

No. Spot metering is a precision tool, and precision tools require deliberate use. In fast-moving situations where you’re raising and firing quickly, Spot metering introduces the risk of the spot landing on the wrong area between frames and producing inconsistent exposures. Evaluative metering is faster and more forgiving in fast documentary or event shooting. Use Spot when you have time to place it intentionally, or when Evaluative is clearly failing you in a specific scene.

Why does my camera keep overexposing or underexposing in Evaluative mode?

Usually because the scene’s average tone is significantly different from 18% grey. Scenes dominated by very bright tones — snow, white sand, a bright sky — will be underexposed because the camera tries to render that brightness as a medium tone. Scenes dominated by very dark tones — a subject in dark clothing against a dark background — will be overexposed for the same reason in reverse. The fix in Evaluative mode is exposure compensation: dial in positive compensation for predominantly bright scenes, negative for predominantly dark ones.

What metering mode should I use for HDR photography?

In Aperture Priority, Evaluative metering is the safer choice for HDR — it balances the full scene and produces a median exposure that gives you a reasonable bracketing center point. In Manual mode, Spot metering gives you more control: meter off a specific mid-tone in the scene to set your median exposure, then bracket above and below it at consistent intervals. Either approach works; the Manual plus Spot combination gives you more predictability over where your bracket is centered.

Does metering mode matter in Manual mode?

Yes, but differently than in semi-automatic modes. In Manual mode, the metering reading is advisory — it tells you how far off your current settings are from what the camera calculates as correct, but it doesn’t change your settings automatically. This means you can use Spot metering in Manual to deliberately meter specific areas of the scene without risk of the camera adjusting exposure unexpectedly between frames. It’s the combination most professional photographers use for controlled, precise exposure work.