Camera Metering Modes Explained (How & When to Use Them)
Hi there! Welcome back to my blog 💚 So far we have covered some of the photography basics like focus modes, shooting modes, how to shoot in manual mode, etc. But the reality is that lucky for me, there is a lot more to know about cameras and photography.
In this post, we will be discussing your camera’s different metering modes, how they work, when to use them, etc. so stick around if this is something you’ve been wondering about.
As we learned previously, your camera takes a picture by letting the light reach the camera sensor. How much light we let into the sensor is controlled but the shutter speed, aperture, and ISO (exposure triangle). To know whether we are over or underexposing, we use the camera light meter.
But how does that light meter know if we are overexposing or not? What kind of dark magic is that? Worry not… I’m here to explain it to you. If you don’t want to learn the ins and outs of your camera metering and only want to learn about the metering modes, click here to get to the good stuff.
Metering System
Your camera has a sensor installed that measures how much light is reaching it and how intense it is. This sensor, also called 'light meter', is a reflective light meter which means that it measures the reflected light from your subject/scene. Nope, that’s not a mistake. It measures the light REFLECTED from the subject.
You may be thinking, aren’t we supposed to know how much light is ON the subject and not reflecting FROM it? Well yes, which is why you have to know how to use your meter properly.
Also, to be perfectly honest, there is an incident light meter which measures the light on the subject which you have probably seen in movies when there is a photographer. I’ve never used it, I learned that it existed and that’s as far as I’ve gotten. But to me, having to run to measure the light, come back to my camera and set it and then take the shot doesn’t make much sense. Also, I don’t think if you are taking a picture of a lion, you’ll be brave enough to get next to a lion to measure the light before running back to your camera.
So, as I was saying, your camera measures the light reflected on the subject. It would be fine-ish if the subject was the same color or at least similar ones so the light was reflected evenly. Of course, this is not the case. To make matters harder (or worse), your camera meter measures 3 tones in a scene. The key point to note is that this scene is in black and white. Therefore, the tones that your camera will be measuring are pure white, pure black and a mid-tone (this doesn’t mean that it’s only measuring the gray tones of the scene but colors too - a mid-tone of any color seen as B&W… hopefully that makes sense).
The problem with this is that your camera meter is going to find those 3 tones in every picture. If it’s a dark scene, like a black swan in a lake on a cloudy day, then it might be that the mid-tones are actually on the darker side and not really mid-tones. Same on a bright scene, for example, a ski field full of snow; even though is closer to pure white, the camera meter will read some of those white tones as mid-tones. What’s the big deal with this? Well, your meter might tell you to overexpose (in the case of the dark scenes) or underexpose (in the case of the bright scenes) because is trying to make those “mid-tones” a mid-tone.
I can show you this with a white piece of paper. So your camera is going to think that this white paper is your “mid-tone” so when we take the picture, the white paper comes out gray.
So how do we fix this? Well, we learn about the mid-tones. Sorry if it’s not the answer you were looking for but don’t panic just yet. Now that you know why sometimes your camera doesn’t do what it’s told to do, we can work around it and if you keep practicing it will come automatically to you.
One thing that helped me to understand what the camera meter is seeing is setting my camera to B&W and then defocusing my scene (see images below). That will show you the tones your camera is seeing. When I see it on the darker side, my camera meter is going to try to make me overexpose so I just stay 1-2 stops under what it recommends. I understand you can’t do this every single time because it will take you a lifetime for each shot but if you do it when possible, you’ll start to get an idea of how your camera meter will operate. Also, the more you shoot, the more you’ll understand your equipment and how far you can push it.
The first picture is how we see through the viewfinder, the second one is how the sensor sees it (in Back & White). The third image helps you see where the mid-tones are.
So if I’m taking a picture of a black bear, I know my camera will try to make me overexpose, but I also know that if I overexpose, my camera will be able to retain details in the highlights and whites if I don’t go over 2 stops (I’m making this up just to prove a point but if you want me to explain a little bit more, let me know in the comments and I will do so). So you can always balance that but again that takes practice, experience, and lots of times and bad pictures.
Now let’s get into the main reason you are here before I loaded you with information to confuse you… (Sorry!)
Metering Modes
There are 3 different metering modes, although nowadays the more advanced cameras will offer you 4. Note that the names might change from brand to brand. I have included the names of Canon and Nikon modes as those are the 2 brands I am most familiar with.
Also, note that the exact science and mechanisms for each metering mode are locked under the biggest Nikon, Canon, Sony, and Fujifilm security boxes. This is part of what makes these systems original and different. So I’m going to explain in general terms how everything works but I cannot go into details because this is unknown unless you work for them and you are ready to get the lawsuit of your life!
Selecting your metering mode
There are 2 ways you can access the different metering modes: via the "i" button (Nikon shooter) and vi the main menu. I've included screenshots of my camera screen so you cans ee what it looks like.
Center-Weighted metering
I believe this is the oldest metering mode there is (maybe I read this somewhere and I’m just repeating like a parrot). This mode does exactly what the name says, it measures the scene as a whole and then gives extra value to the center area. How much? I’ve researched to try to find a number and I found a range between 60% - 80%. Steve Perry from Back Country Gallery mentioned 75% and to be honest, that guy knows a lot so we will go with that. So the center area has 75% more weight than the rest of the scene.
So in scenes where your subject is in the middle, this is a good metering mode to use. Now, be aware that this does not work like focus where you can lock the focus and then recompose. Your camera will continue to measure light at the different spots giving more importance to the center area of your viewfinder.
Most pro and mid-range cameras will have an option of adjusting the center area size. I’ve included pictures of where to find it in a Nikon camera below. If you have any other brand, check your camera manual.
Spot Metering Mode
Just like the name says, spot metering reads off of a spot in the scene. It is quite small though, especially for full frame cameras so keep that in mind. Unlike the center-weighted metering, nothing else outside of the “spot” is accounted for the reading.
It is very important to note that this metering mode does get affected by the focus mode you choose to use. The light meter will take a reading from the primary point so if you are using Autofocus, your camera will be able to focus on your subject if it’s moving around but your light meter will still be measuring the light from the main point you’ve set up.
This doesn’t mean you shouldn’t use it. This is a really good mode but you need to understand how it works so you can take advantage of it.
Where should I place the focus point to get the right reading? In the mid-tone area! By doing so, your camera will prioritize the mid-tones and not over or underexpose your scene. Just remember that if you are locking the focus and recomposing, make sure to move that AF point so you can get an accurate reading.
Matrix Metering Mode
Also known as Evaluative Metering for Canon users, this measuring system has evolved with time (as it should) but to spare you the details we will just jump into how it works now.
The camera divides the scene into segments. How many? I am not sure because it depends on the camera and brand but it is in the hundreds. All of these segments constitute the “matrix” which calculates the levels of brightness and patterns to come up with an appropriate exposure.
This mode also considers your AF point because the system assumes that where you are placing this point, is because there is something you want to focus on.
Now, I should mention that there is a lot more that this mode considers but I don’t want to overwhelm you. If this is something you are interested in, please let me know in the comments and I can do a deep dive into this metering mode. Do you really need to know every single detail? No, definitively no. But knowledge is power. So if sometimes your camera is not doing what you want it to do, knowing these things might give you some answers.
This mode is probably my favorite for the type of work I do. However, when you are in very bright/dark situations, due to the lack of tonal range, your camera might make the camera struggle to give a correct meter reading. Nevertheless, if your scene doesn’t have too many tones BUT is mostly covered with mid-tones then your camera will nail it every time.
Highlight Weighted Metering Mode
This option can be found in the newer camera versions. A lot of people say that this is a type of spot metering but the truth is, it is a type of matrix metering. Why? Because it measures the whole scene instead of just one spot. How it works is that it detects the areas with large amounts of highlights and adjusts the exposure to protect those areas.
This is a great mode if you have a scene that is in danger of clipping because the camera's light meter will make sure the exposure is adjusted accordingly. The problem with this is that if you have a very bright little area, it will throw your exposure all out of whack. For example, a window where a lot of light is coming through, you might end up with a black room with a very clear view of what’s outside the window.
Partial Metering Mode
This is a Canon-only metering mode and it covers only the center 6.2% (percentage obtained from Canon Hong Kong website) of the frame in the viewfinder.
I cannot tell you much about it because, as you know, I’m a Nikon user. I can get a Canon camera and explore this mode a little bit more if you
What metering mode should I use?
Well first of all as you may have noticed, a lot of the metering modes overlap each other. Also, the metering mode you choose will help your camera assess the entire scene in a particular way. If your camera is giving you a reading that you don't think is correct (for example when you use mirrorless cameras you can see the adjustments before taking the shot), you can always adjust the settings DEPENDING on your shooting mode.
If you are in control of your exposure settings completely (like in Manual mode), then your exposure metering will give you an idea of what to change but it's up to you as the photographer to do as you see fit. If you are using any of the auto-shooting modes (or semi-automatic modes) then you'll need to be more precise with your camera metering mode and how to use them.
Nevertheless, you can achieve any photo with any of these metering modes. The trick is to understand how they work and to practice.
Below I have included a picture of my beautiful model using each mode. As you can see the exposure changes from one picture to the other but nothing dramatically (except maybe for the highlight-weighted metering mode where the picture is heavily underexposed).
I normally use the Matrix metering mode (or Evaluative metering mode for Canon cameras). I think this is the best general metering mode and it works in 90% of the scenarios I shoot.
I use the spot metering mode when I am shooting a very dark or bright scene so I can choose what the mid-tone area is and get a proper reading.
Other than that, I do not use any of the other modes. I personally don't need them but that doesn't mean you won't need them either. Again this all comes to experience so get out there and shoot as much as you can and let me know if this post helped at all.
Happy shooting!
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