Metering modes and how exposure metering works

Controlling exposure part 2: metering modes

In the second part of our series on controlling exposure we’re looking at how exposure metering works and metering modes. Understanding your camera’s exposure meter is essential to understanding how your camera works and then moving on to photographing in manual mode.

But let’s not jump in at the deep end yet. Let’s first understand how exposure metering works and why you need to know it.

If you missed part 1, you can find it here – How to read a camera’s exposure meter

What is meant by exposure metering?

When you measure the exposure of a scene, you are measuring the brightness of a scene so that either you (in manual mode) or your camera (in all other modes) can set the aperture, shutter speed and ISO for a correct exposure.

If the scene is not measured accurately your photo will be underexposed or overexposed.

Understanding how exposure metering works for accurate exposures

Two ways to measure brightness of a scene:

  • A handheld light meter
  • Your camera’s inbuilt metering system

In this article we’re specifically looking at how a camera meters light, which is the light reflected off the subject, in different metering modes.

Further reading: Why you need an incident light meter

In auto you have no control over exposure metering, which is why it’s best not to use auto. You can set metering modes for your camera’s metering system in:

  • Program mode
  • Aperture priority mode
  • Shutter priority mode
  • Manual mode

What does metering mode mean?

A metering mode is the camera setting you choose to measure exposure. When you select a metering mode to measure the brightness of a scene, you decide what part of the scene you want correctly exposed.

So deciding on a metering mode is your first decision when setting exposure.

What are the different metering modes?

There are three exposure metering modes for Nikon and four for Canon. The symbols for the different metering modes vary between brands, as do the names:

  1. Spot metering
  2. Partial metering (Canon only)
  3. Center-weighted metering
  4. Matrix metering (Nikon), evaluative metering (Canon), zone metering (Sony)


What’s the difference between the metering modes?

Spot metering

Meters the brightness of a specific area that you’ve selected, which is about 2 – 4% of the scene.

Use this when the light is coming from behind your subject, like when you’re indoors photographing a subject in front of a window. Your background may be overexposed, but your subject will be correctly exposed.

Further reading: When to use spot metering?

Partial metering (Canon only)

Meters 8 – 13% of the center of the scene.

This, like spot metering, is really useful when your subject is darker than the background, such as when your subject is backlit.

Centre-weighted metering

Meters the area around the center of the scene, which is about 60 – 80% of the scene, regardless of your focus point.

Matrix metering (Nikon) or evaluative metering (Canon)

Meters the overall brightness of the entire scene, so is ideal when the scene is lit from the front.

Learning when to use each of these types of metering will make a big difference to your photography.

understand how exposure metering modes work

What’s the point of different metering modes?

If the camera knows what part of the scene you want correctly exposed, it’ll be able to do what you want it to do.

Having a choice of different metering modes to use in different situations gives you the ability to meter the exposure in part or all of the image, depending on your needs.

Things to watch out for

Because your camera measures reflected light and is designed to average the exposure out to an average midtone (that’s medium gray if you’re thinking in black and white), it’ll struggle when the scene is either dark or light.

Easy to meter scenarios are scenes without much contrast between light areas and dark areas, such as a brick wall, your back garden on an overcast day, a green landscape. Anything that’s evenly lit and doesn’t have huge variations between lights and darks.

Further reading: Midtones in photography – how to see and use tones for better pictures

Dark scenes

Because your camera measures the scene to expose it at an average tone, when faced with a dark scene, it might overexpose the scene as it tries to lighten the dark tones.

How to meter a dark scene to ensure a good exposure

Light scenes

On the other hand, if the scene is very light, such as a field of snow or a white building, your camera will read this as very bright and will underexpose the scene.

Knowing this allows you to take control when faced with challenging situations for your camera’s exposure meter.

Further reading: How to use the zone system in photography for perfect exposure

You have three choices to help your camera measure a scene correctly:

  • Meter off a midtone within the scene
  • Meter off a gray card
  • Use exposure compensation

We’ll look at the first two below, but will look at exposure compensation in part 3 of this series on controlling exposure.

How to meter a bright scene with a lot of white

Where to find midtones in a scene

  • Healthy green grass
  • Light stone wall
  • Blue sky (with the sun behind you)

How to meter off a midtone in a scene:

  • Select spot metering on your camera
  • Point it at the midtone area to assess the exposure
  • Adjust your ISO, aperture and shutter speed as needed
  • Start photographing

What is a gray card and how to use it for exposure metering?

Gray cards are exactly that – medium gray non-reflective material.

They don’t cost much and can be bought from from a camera dealer, or online. I use a Lastolite fold away gray card that looks like a really small pop up gray reflector (it’s the Lastolite EzyBalance 12 inch – 18% Gray / White).

How to use a gray card if you’re photographing a person:

  • Ask them to hold up the gray card
  • Aim your camera at the grey card
  • Put your camera into manual mode
  • Meter the exposure
  • Adjust ISO, aperture and shutter speed
  • Focus and start shooting

If the light changes, or you change your position, meter again, but otherwise you’re good to go.

Before taking a photo, get into the habit of asking yourself what metering mode would be best for the situation.

How to use a gray card if you’re photographing a scene without a person in it:

  • Position the gray card in the scene facing you
  • Meter off it as above
  • Remove it from the scene and start shooting

Further reading: How to use a gray card to meter exposure

Don’t miss out

If you don’t want to miss when new photography tutorials are published, pop us your email address. You’ll receive our metering mode cheat sheet instantly as a bonus and every week we’ll send you our bulletin of helpful tutorials to keep you on track to taking the photos you dream of.


Missed Part 1? Here it is…

Read Part 1 of Controlling Exposure – How to read a camera’s exposure meter

Part 3 – How and when to use exposure compensation

The exposure metering system on your DSLR camera can be fooled, such as when shooting in snow.

We look at the different situations that will confuse your camera and what you can do about it. This is exposure compensation.

Go to: How and when to use exposure compensation

Part 4 – How to control exposure in all shooting modes

Maybe you want a faster shutter speed or shallower depth of field?

The camera doesn’t know how to achieve creative results, it only knows how to give an accurate average exposure reading for the area that’s being metered.

We look at when and how to use program mode, aperture priority, shutter priority and manual mode for creative results and controlled exposure.

Go to: How to control exposure in all shooting modes

Part 5 – Pros, cons and how to use auto ISO

Sometimes there’s so much going on that you need a little auto help. We look at the benefits and limitations of using auto ISO – even in manual mode!

Go to: Auto ISO – pros, cons and how to use it

Leave a comment

If you have any questions about the best metering mode to use or how to use the different metering modes, leave a comment and I’ll get back to you with some help.

Also, I love good news, so if my exposure metering tips have helped you to understand how exposure metering works, share that too.

9 thoughts on “Metering modes and how exposure metering works”

  1. Thank you for this. I have taken some blog photos every now and then, and hadn’t given metering any thought. I didn’t even know what it meant. English is not my first language – so I didn’t think it was important. 😛 Thank you.

  2. Thank you once more for such an informative article on exposure and all the relevant settings. The explanations are so good that it is straight forward to follow and implement.

  3. Jane, this blog series on controlling exposure is something special! I have a question: When you half press the shutter button, the camera determines exposure based on two things: (1) the quantity or intensity of the light in the scene and (2) the subject, right or wrong? In other words, is the camera’s exposure metering light- AND subject-centric?

    Let’s say, for example, I am shooting an indoor basketball game. The light is constant. My shooting mode is Manual. I set my exposure settings based on the light in the gym and then get ready for the action. I know that in Manual Mode, my settings will not change without my input. When I choose a player to make a photo of, how does his skin tone play with the exposure settings I set in Manual Mode?

    Thank you for all this remarkable and thorough content!

    • Hi Janine

      Yes, that’s exactly right. Because your camera meters light that’s reflected off your subject, darker colors, which absorb light, will reflect less light than light colors. This is why white material is used to reflect light to fill in shadows and black material is used to absorb light for negative fill to deepen shadows.

      So when you meter your exposure, it’s ideal to meter off something that is medium gray, such as a gray card, or even normal healthy grass. If you can’t do that … (because you’re not going to chase a basketball player around the court and ask him to hold up a gray card so you can get your exposure dialled in)… and you’re using spot metering to meter off skin, then you need to think about how his skin color will affect the exposure reading and if you need to compensate up or down.

      The difficulty with setting your exposure for the light in the gym is that sometimes the players will be closer to the light than other times. Sometimes they’ll be facing up to the light and other times they’ll be looking down, so their faces will be in shadow. If they’re wearing white shirts light will be reflected back up when they look down, which will help.

      So, you need to become very familiar with your camera and be constantly aware of the exposure indicator so that you can quickly adjust shutter speed or aperture.

      Alternatively, set your exposure in manual mode and then use Auto ISO, but limit it. My preference would be to adjust the aperture rather than use auto anything. Here’s a tutorial on Auto ISO –

      Also, think about when you set your exposure – how did you meter the light? Was it off a non-reflective, medium gray surface where the players would be?

      I think you’ll find this tutorial on the zone system will bring it all together for you –

      I hope I’ve helped and haven’t bombarded you with too many what ifs. Great to hear your feedback on my controlling exposure series – thank you!

  4. This section has a paragraph that mentions three choices to help your camera meter a scene correctly under difficult lighting conditions. The choices shown are midtone, gray card, and exposure compensation. These three choices depend on the camera’s built-in reflective light meter, which can be fooled by a light or dark object. There is actually a fourth choice, which is better than the aforementioned three choices. That choice is a hand-held light meter, which measures incident light. With a hand-held light meter, you get the best and most accurate reading, which will effectively enable you to eliminate the first three choices.

  5. Thankou for a very informative tutorial. I have learnt a lot. Never used the various metering modes. Started using manual so out of my comfort zone. Now know how to adjust exposure.
    Not sure if I have understood correctly but I have mainly used aperture and shutter priority and my camera shows + & – EV in both settings. Did you say if I adjust the + & – the camera will overule and compensate for the change thus defeating the change.
    Can you also advise when taking pictures of flowers the edges of the petals are white or burnt out. Tried changing ISO, shutter and aperture but didn’t work. Now know how to adjust exposure and metering mode so will try again tomorrow.


Leave a Comment