Metering Modes Cheat Sheet

What is a Light Meter?

Your camera’s light meter is a built-in tool that determines the overall exposure of your scene. 

Cameras use the light meter to choose the appropriate exposure settings in auto, aperture, and shutter priority mode. 

How does the Light Meter Work? 

The camera’s light meter is programmed to interpret light as if it were reflecting off a neutral grey surface. That is, when taking a photo, your camera turns colors into tones of grey.

Shadows are converted to shades of black and dark grey.

Highlights and bright colors are converted to shades of light grey and white. 

And midtones are converted to mid-grey.

The light meter perceives darker shades of grey as underexposed, mid-grey as correctly exposed, and lighter shades of grey as overexposed. 

Your light meter then averages out all the grey shades to determine the overall exposure of your scene. 

The camera meter’s baseline for proper exposure is 18% reflectance in visible light (middle grey).

If you are in shutter or aperture priority mode, your camera will adjust your exposure settings to create a scene exposed for middle grey.  

Resource: What is Middle Grey: Understanding 18% Grey Reflectance

How Does Your Camera Measure Exposure?

Your camera measures exposure on the exposure value scale. 

The exposure scale is a small series of bullets accompanied by numbers located on the Live View display or the LCD screen on top of your camera.

The values range from negative three to positive three. 

Negative values indicate an underexposed photo. 

Positive values indicate an overexposed photo. 

And an exposure value of zero indicates a properly exposed photo. 

When you adjust your exposure settings, your exposure value will change accordingly.  

The goal when setting your exposure is to have an exposure value of zero or close to zero.

Metering Modes

Digital cameras have different metering modes. 

Each metering mode emphasizes a different portion of your scene when calculating your exposure. 

As a result, the metering mode you use will have a massive impact on your scene’s overall exposure reading. 

Your choice of metering mode will depend on what subject you want to expose properly and the type of photography. 

Most cameras come with three different metering modes: matrix, center-weighted, and spot. 

Different camera brands apply different methods to each metering mode, but the overall logic remains the same. 

As a result, your exposure measure might differ between camera brands, even if you are using the same metering mode. 

1. Matrix/ Evaluative Metering Mode 

Matrix metering mode is the default setting on most cameras and the most common settings used by photographers. 

Matrix metering goes by several different names depending on the camera brand. 

The equivalent of matrix metering mode for Canon cameras is evaluative metering. 

Other common names for matrix metering is average, multi-segment, and even zone metering. 

Regardless of the camera brand, this metering mode applies the same logic when determining your scene’s exposure. 

Matrix metering mode uses the light from your entire scene and averages it out to determine the overall exposure of your scene. 

In most cases, in matrix metering mode, your scene is divided into sections. 

The exposure of each section is calculated and then averaged out with the remaining sections to determine the overall exposure of your scene. 

Here is an example of how the sections can be divided up in matrix metering mode. 

The exact sections of the image may differ based on the camera you are using. 

There is lots of conjecture online that in matrix metering mode, the center of your image is emphasized slightly more than the rest of the frame, but there is no proof of this. 

It is more likely that the section where your focus point is located will receive more emphasis. 

While how much emphasis the focal point receives is not certain, it is clear that it will shift your exposure. 

1.1 When to Use Matrix Metering Mode

Matrix metering is the best option if you are new to photography. 

It will produce an image with the most average exposure. 

It is unlikely to produce an image that is extremely overexposed or underexposed. 

This is a great option to preserve as much detail in your image as possible. 

Matrix metering will give you the greatest flexibility if you want to edit your photos in post-processing. 

This setting is also effective when you are shooting evenly lit scenes. 

When shooting evenly lit scenes, matrix metering will properly expose most of your scenes. 

This is because the average exposure produced by matrix metering will adequately expose a scene with uniform lighting. 

Matrix metering is also effective when you want to properly expose your entire scene. 

This is the reason many landscape photographers shoot in matrix metering. 

It will produce an image with an average exposure, meaning that it’s likely all your elements will be slightly overexposed or underexposed. 

Unfortunately, matrix metering is not effective when shooting high contrast scenes. 

In high contrast scenes, matrix metering will produce an image with overexposed shadows and underexposed highlights. 

2. Center-Weighted Metering

As the name suggests,  in center-weighted metering the center of your image is given more weight than the rest of your image. 

The rest of your scene is still considered when determining the exposure of your image. 

The size of the center portion of the image may differ depending on the camera you are using. 

Some DSLRs allow you to adjust the size that your camera treats as the center. 

Not all camera brands make the calculation clear when shooting in center-weighted metering. 

Nikon states that it gives the center of the frame receives approximately 75% of the exposure calculation, while the rest of the frame accounts for 25% of the exposure calculation. 

2.1 When to Use Center-Weighted Metering

Center-weighted metering is most effective when your subject is at the center of your frame. 

Portrait and abstract photography will benefit the most from shooting in center-weighted metering. 

When shooting these types of photography, it is common to place your subject at the center. 

This will ensure that your subject is exposed correctly regardless of the lighting at the edges of your frame. 

Center-weighted is also a great option if you are shooting with backlight. 

Keep in mind, center-weighted metering will most likely overexpose your background. 

This is a common effect when shooting a portrait or other types of photography. 

If this is your goal, this is a great way to properly expose your subject while intentionally overexposing your background. 

3. Spot Metering 

Spot metering is the most precise and accurate metering mode. 

It evaluates one specific section of your image and determines the exposure using that “spot” while ignoring the rest of the image. 

Spot metering typically takes between 1% and 5% of your scene, depending on your camera when calculating the overall exposure. 

Your focal point determines the “spot” or area of your scene that is evaluated. 

Only considering a small portion of your image can have benefits, but there are also disadvantages.

Spot metering ensures a specific portion of your image is properly exposed. 

But, this can result in the rest of your photo being overexposed or underexposed. 

Spot metering is a great way to take control over the exposure of your image. 

By adjusting the location of your focal point, and depending on how dark or bright it is, you can drastically change your entire scene’s exposure. 

For example, if you choose a dark area of your image, it will make your entire image brighter. 

Likewise, if you select a bright area of your image, it will make your entire image darker. 

You can use spot metering to control how you want to shift your exposure. 

3.1 When to Use Spot Metering

Spot metering is most effective if your subject only takes a small portion of your image. 

I recommend using spot metering if you’re shooting wildlife or portrait photography. 

Often when shooting these types of photography, spot metering is perfect for properly exposing your subject. 

For example, if you are shooting bird photography with a telephoto lens, using spot metering is a perfect option to properly exposure the birds. 

Spot metering is also great for creating silhouettes. 

To use spot metering, move your focus point to the brightest area of your frame and press the shutter button halfway down. 

Then you can readjust your focus and take your image.

Another great time to use spot metering is when your shooting high-contrast scenes. 

With spot metering, you can select exactly what portion of your images you want to expose your highlights, shadows, or midtones properly.  

4. Partial Metering 

Partial metering is a common setting found on Canon cameras but not always found on all camera brands. 

Sony has a similar option, which is called large spot metering. 

Partial metering is very similar to spot metering, except a bigger portion of your image is evaluated when calculating exposure. 

For example, in spot metering, 1% to 5% of your frame is used to calculate exposure while partial metering typically uses around 5% to 10% of your image. 

Just like spot metering, only a section of your image is evaluated while the remainder of your image is ignored. 

Partial metering is excellent if you want to use a specific portion of your image to evaluate your exposure. 

While sport metering is limiting due to how small it is, partial metering is an excellent alternative if you need to use a larger portion of your image evaluate your exposure. 

Remember that not all cameras have a partial metering mode, specifically Nikon cameras. 

Most Nikon cameras allow you to adjust the radius of spot metering.

This is a great way to overcome a lack of partial metering on Nikon cameras. 

4.1 When to Use Partial Metering

Use partial metering in similar situations as you would spot metering. 

The only benefit that partial metering offers over spot metering is that the area is larger. 

Portrait photography and wildlife photography are both great options to use partial metering. 

Problems with Metering 

Light meters don’t intrinsically understand the level of exposure you are trying to reach. 

In complex lighting conditions, this is problematic since one lighting adjustment won’t allow you to expose the different lighting conditions in your image properly. 

Since light meters expose for mid-tone grey, they can often misinterpret the exposure for a scene.

Mid-tone grey is often not the proper exposure for all scenes.

For example, if you are shooting a scene with lots of bright elements, your light meter is likely to misinterpret it.

Your light meter will likely underexpose your image to account for the bright elements. 

Due to the light meters’ fundamental issues, it will not always interpret a scene correctly.

In addition to the light meters difficulty exposing images, different metering modes tend to make you compromise parts of your image. 

Matrix metering averages out your entire scene but doesn’t properly expose any one part of your image. 

Spot metering and partial metering will only properly expose a small portion of your image while ignoring the rest of your image. 

Center-weighted metering will only properly expose the center of your frame. 

Exposure Compensation and Metering Modes

As mentioned above your cameras light meter is not perfect. 

Since our world is not grey, there will be instances when the camera will provide an incorrect interpretation of reflectance. 

For example, if you are shooting in the snow, your camera is likely to interpret your image as overexposed. 

This is because the white snow is typically twice as bright as grey. 

But your camera’s light meter doesn’t intrinsically know that.

As a result, your camera will try to reduce your exposure to account for the bright nature of the snow. 

One way to overcome this issue is by using your exposure compensation. 

Exposure compensation allows you to adjust your exposure without changing your settings. 

Your exposure compensation will adjust what your light meter treats as proper exposure. 

Exposure compensation allows you to reduce your exposure or increase your exposure by up to 5 stops depending on your camera. 

For example, if you increase your exposure compensation to EV+1, your light meter will expose your scene for one-stop over-exposed. 

Likewise, if you set your exposure compensation to EV-1, your light meter will expose your scene for one stop underexposed. 

In the case of your of shooting in the snow, you would want to increase your exposure compensation to positive value to adjust for the light meters misinterpretation. 

Exposure compensation is a great way to control overcome the intrinsic issues with your light meter and control the exposure of your scene.