Light Metering Modes, and When to Use Them

Mirrorless, DSLR, and Film cameras have multiple light metering modes. Each mode is designed to work in a specific lighting situation so that the photographer is completely in control of every frame that they photograph. So, how does one know which mode is the most appropriate for any given situation?

As with most things related to photography, the answer is to get to know your equipment a little better. In this article, we start by understanding what a light meter does, and then we look at what each mode does. Now, let’s look at four of the most often-used camera metering modes, and how you can use them.

What Does a Camera’s Light Meter Do?

A camera’s light meter’s job is to analyze the amount of light reflecting off the subject, and coming through the lens onto the sensor. Based on this analysis, the photographer (or the camera’s processor), can set appropriate shutter speed, aperture, and ISO settings to get a well-exposed image.

The light that comes through the lens is analyzed using multiple sensors inside the camera. In mirrorless cameras, the image sensor can directly read light values, but in DSLR and Film cameras, light must be directed onto specific sensor locations to allow the camera’s built-in processor to select the correct exposure settings.

The different metering modes give different segments of the camera’s frame different weightage and importance, and as such can be used for different, specific, purposes. Some of the different modes in a camera are:

  • Multi-Segment Metering Mode or Matrix/Evaluative Metering Mode
  • Center Weighted Average Metering Mode
  • Partial Metering Mode, and
  • Spot Metering Mode

What Does a Light Meter Consider to be Well-exposed?

An old Sekonic L-208 Light Meter on a camera. Photo by JE Labs

A light meter by itself does not know what you want the photograph to look like. Instead, it understands that most scenes are reasonably well exposed if they’re averaged to a “mid-grey“. So, the light meter’s job is to make the picture 18% grey (aka Mid Grey).

Today’s cameras have algorithms that understand what a camera’s sensor is looking at (for example a face, animal, bird, etc.). The complex AI or ML algorithm has been trained on thousands of scenarios and knows to prioritize those areas, over other areas of a photograph. They do this by using multiple data sources such as pixel color, distance to the object, and more when setting the exposure.

However, older DSLR cameras and film cameras did not do that. They either sensed how much light was coming into the lens overall, or how much was landing on specific areas of the frame. How the light meter reacted to these ‘zones’ of sensitivity determined which areas were given priority.

The areas that were given priority based on the photographer’s selection would be averaged to ensure a correct exposure would lead to a mid-grey tone. Of course, that leads to its own issues with under and over-exposure in certain unusual situations, but that’s best dealt with in a different article.

In this article, let’s take a look at the various metering modes that you’re likely to encounter on a DSLR or Film camera in order of decreasing difficulty. In the illustrations below, we’ve used the colour red to mark the areas that are being used for light metering in every mode.

Now, let’s explore the different light metering modes:

1. Spot Metering Mode

Representation of Spot Metering Mode in a camera's viewfinder.
Representation of Spot Metering Mode in a camera’s viewfinder. Red area is metered.

Spot meters read reflected light from a very narrow angle of view; usually just 1 degree of view. Photographers used to use hand-held spot meters which were expensive and very specialized in function. Cameras replicate this functionality to some degree, by reading light off a very small area in the center of the focusing screen. Often, the area being metered is just 1-2% of the entire frame’s area.

When Should You Use Spot-Metering Mode?

Spot metering is especially useful in contrasty lighting, or when a certain small area of the frame When exposure in a certain area is critical, and there is a lot of contrast in a scene. For example, when you’re shooting a concert, you may face very bright or very dark stage settings. If exposing for the entire scene, you may risk blowing out the artist’s face to an over-exposed white.

However, with spot metering,you can meter off their face, and when set to manual, you’ll be exposed correctly most times. Most regular metering modes will have trouble getting the right exposure for just the artist’s face.

All you have to do is point the center dot at the spot that you want to be exposed correctly, set your exposure manually, or use the exposure lock button, and take your photograph.

What Else Is It Good For?

It’s good for measuring the contrast range of a photograph and deciding your exposure based on multiple readings. You can do this when you want to get really technical about your exposure, but for most people and purposes, it’s not necessary with today’s technology.

Level of Difficulty

Difficult

2. Partial Metering Mode

Representation of Partial Metering Mode in a camera's viewfinder.
Representation of Spot Metering Mode in a camera’s viewfinder. The Red area is metered.

Partial metering is very much like spot-metering, but reads light from a 10-15% area around the center of the viewfinder. Unlike Center-Weighted metering, There is no weightage. This makes it useful for contrasty lighting situations where there are larger elements in the scene.

When Should You Use Partial Metering on Your Camera?

Use it in situations where you need to accurately meter an area of your frame that’s slightly larger than a 1-degree spot. It’s also useful if you need to average out the lighting in a certain region, but where the area that is under similar lighting is slightly larger. Useful in back-lit situations.

Level of Difficulty

Intermediate

3. Center Weighted Averaging Mode

Representation of Center Weighted Averaging Metering Mode in a camera's viewfinder.
Representation of Center Weighted Averaging Metering Mode in a camera’s viewfinder.

This is the kind of metering that most manual film cameras had by default until. It reads about 80% of the scene, giving more weightage to the center of the frame. This is because most people compose their photographs with the subject in the center.

Think of a box just inside the viewfinder’s edges. This is the metered area. However, there is a circular aread in the middle which is given more importance in determining the exposure to be set.

Some manufacturers also add a little extra weightage to the bottom of the central circle. I guess that they’re assuming that in a scene being photographed, the subject would not be pointing down from the sky.

When Should You Use Center Weighted Averaging Metering?

Use this metering mode when you’re shooting with more or less even lighting in your scene; for example, when the light is behind you, and you’re shooting with your subject in the center of your frame. It is also useful in scenarios where the edges of the scene are dark, and may influence the metering exessively.

Most family and group pictures fall into this category. It’s an all-purpose light metering mode, but one that has now become outdated because of the invention of multi-zone metering systems.

Level of Difficulty

Normal

4. Multi-Segment Metering Mode

Representation of Multi-Segment Metering Mode in a camera's viewfinder.
Representation of Multi-Segment Metering Mode in a camera’s viewfinder.

Multi Segment metering is also known by proprietary names such as Matrix Metering (Nikon), Evaluative Metering (Canon), Honeycomb Metering (Minolta), and others…

Multi-segment metering divides up the frame into different parts, which are then evaluated for exposure separately and compared against a database of lighting situations that are stored in the camera’s processor. The camera then selects an appropriate exposure setting.

When Should You Use Multi-Segment Metering?

Today, the cameras we use are quite well-programmed, and for most purposes, there’s no need to ever take your camera off whichever Multi-Segment option your camera manufacturer provides. However, there are some lighting scenarios that prove to be too difficult for the camera to handle. Knowing this comes from knowing your equipment, and from using it often.

Level of Difficulty

Easy

Metering on Modern DSLRs and Mirrorless Cameras

Today’s cameras are very intelligent. They literally can detect what the lens is capturing in real-time.

For example, Sony, Canon, and Nikon mirrorless cameras have eye focus which allows the autofocus to lock on to features of a person or animal’s face. Some cameras even detect automobiles, birds and more. All this data also informs the camera about which areas are important and can be used to pick an exposure to favor these areas when used in automatic modes.

We’ll look into metering on mirrorless cameras in a future article, so subscribe to our email newsletter or social media to stay in the loop.

Want To Know More?

Let us know if you’ve got any questions about metering light for photography. Also, feel free to leave suggestions in the comments.

References:

Featured Image by Christopher Burns

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Help Us To Continue Creating

Get our email newsletter to stay up-to-date with our latest posts. It’s easy to read and is mailed once in 2 weeks.

The easiest way to support Beyond Photo Tips is by using our affiliate links when you buy anything at all. It will never cost you anything extra, and we get a small commission from it, which helps us a LOT! We share our recommended equipment list here.

Some of the links to products on this website are affiliate links, and we only ever link out to gear that we recommend.

You could also show your appreciation by buying us a coffee. Finally, we appreciate you being a part of the community, so do say hi!

Susheel Chandradhas
Susheel Chandradhas

Susheel Chandradhas is a Product Photographer and Filmmaker based in India. He has been taking photographs (almost) all his life. He has a diploma and a bachelors degree in Visual Communication, where his classmates all believed that he would write a book on photography... Instead, he writes on this website (because - isn't a community more fun?).

His passions include photography, parkour, wide-angle lenses, blue skies, fire extinguishers, and fast computers.

In addition to writing for Beyond Photo Tips, Susheel is a staff writer for Fstoppers.com, and owns and runs ColoursAlive, a photography, and video production studio.

You can connect with Susheel on Twitter, Instagram, or LinkedIn.

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