Understanding Metering and Metering Modes

Modern DSLRs have a “Metering Mode”, also known by “Exposure Metering”, “Camera Metering”, or simply “Metering”. It is crucial to understand how metering works in photography. This helps photographers take better photos in difficult lighting conditions and control their exposure. This article will help you understand metering modes and explain how it works.

One of the things that frustrated me about my Nikon D80 DSLR was the way some images turned out. It was a frustrating problem that I didn’t know how to fix until I discovered camera metering modes.

What is Metering?

Metering is the process by which your camera determines the shutter speed and aperture, depending on how much light it receives and the ISO. Cameras didn’t have a light “meter” back in the early days of photography. This sensor measures the intensity and amount of light. To determine the best exposure, photographers had to use hand-held light meters. Because the work was on film, the photographers could not see or preview the results immediately. This is why they relied so heavily on the light meters.

Nikon Viewfinder

Every DSLR today has an integrated light-meter, which automatically measures the reflected sunlight and determines the best exposure. These are the most popular metering modes for digital cameras:

  1. Matrix Metering, also known as Evaluative Metering or Canon
  2. Center-weighted Metering
  3. Spot Metering

Partial Metering is also available on some Canon EOS models. However, the area covered is much larger than Spot Metering (approximately 8.5% of the viewfinder area in the center vs 3.5% for Spot Metering).

When you shoot in Manual Mode, you can see the camera’s meter in action – just look in the viewfinder to see bars moving left or right with a zero at the center, as shown below.

Matrix Metering

If your camera is pointed at a bright area, the bars will turn to the “+” side. This indicates that there is not enough light to allow for the current exposure settings. If your camera is pointed at a dark area, the bars will turn to the “-” direction, which means that there isn’t enough light. To get to “0”, the optimal exposure according to your camera meter, you will need to adjust your shutter speed.

Camera meters are not limited to Manual Mode. When you select another mode, such as Aperture Priority. Shutter Priority. or Program Mode, the camera adjusts the settings automatically based on the information it receives from the meter.

Metering problems

Camera meters work well when the scene has been properly lit. It can be difficult for light meters to determine exposure when different objects are present. If you take a photo of the blue sky without any clouds or sun, it will be properly exposed because only one level of light is needed. It becomes a bit more difficult if you include clouds in your image. The camera meter will now need to assess the brightness and brightness of the sky to determine the best exposure. The camera meter may adjust the brightness of the sky to expose white clouds. Otherwise, they might look too white.

Center-weighted Metering

What would happen if you put a mountain in the scene? The camera meter would now see that there is an object large enough to make the scene darker than the clouds and sky. It would then try to find something in the middle to expose the mountain. The default camera meter examines the whole frame for light levels and attempts to find an exposure that balances both the bright and dark parts of the image.

Matrix/Evaluative Metering

Most DSLRs default metering mode is Matrix Metering, or Evaluative Measuring. This works in a similar way to the previous example. It divides the frame into multiple “zones”, and each zone is then analyzed individually for light and dark tones. The camera’s focus point affects matrix metering. This is in addition to color, distance and subjects. After reading all the information, the metering system examines the focus point within the frame and assigns it a higher priority than the rest. The equation may also include other variables that vary from manufacturer to manufacturer. Nikon, for instance, compares image data with a database that contains thousands of photos for exposure calculation.

Spot Metering

This mode should be used for most of your photography. It will usually do a good job in determining exposure. For most of my photography needs including portraits and landscape photography, I use matrix metering with my camera metering.

Center-weighted Metering

It is not always possible to use the entire frame to determine the right exposure. How about if you want to take a portrait of someone with the sun behind them? Center-weighted Metering is a great tool for this. Center-weighted Metering looks at the light in the center of the frame and the surrounding area and disregards corners. Center-weighted Metering is not like Matrix Metering in that it does not consider the focal point and instead evaluates the image’s middle.

This mode is used when the camera wants to prioritize the center of the frame. It’s great for portraits or large subjects in the middle. This mode, for example, would allow you to expose the face of a person when the sun is behind them. However, everything else would be overexposed.

Spot Metering

Spot Metering evaluates only the light surrounding your focal point. It ignores all other factors. Spot Metering only evaluates one cell/zone and calculates exposure based solely on that area. This mode is a favorite of mine for bird photography. The birds occupy a very small area in the frame so I have to ensure that they are properly exposed regardless of whether the background has a bright or dark background. The light is measured where my focus point is, so I can get a precise exposure even if the bird is at the corner of the frame. If you are taking pictures of people with the sun behind them, but only occupy a small portion of the frame it is better to use spot metering mode. If your subjects are not taking up much space, Matrix and Center-weighted Metering modes will most likely produce a silhouette. Spot metering is great for subjects that are backlit.

Spot metering can also be used to photograph the Moon. Spot metering is the best option because the moon will take up only a small amount of the frame, and the sky is completely black around it.

Multi-spot metering is a feature of some DSLRs, such as the Canon 1D/1Ds. This allows you to choose multiple spots to measure light, and then calculate an average exposure value.

How to change the camera metering mode

This varies from one manufacturer to the next, as well as from model to model. For example, the Nikon D5500 has a menu setting (Info button) that allows you to do this. Professional cameras, such as the Nikon D810 or Nikon D5, have a separate button at the top of the dial that allows for camera metering. Canon cameras have different metering settings. However, they can be changed by using a key combination (the “Set” button), a camera menu, or a dedicated button near the top LCD.