Metering Modes

Metering Modes!

First of all, what is metering? Metering when referred to photographically is the camera's calculations to acquire proper exposure. When the camera is metering it is essentially calculating the brightness of the light that is entering the camera. It will then take an average of the light and turn it into what is called middle gray, or 18% gray. We'll get into the 18% gray conversation in a later article, but for now just know that the light is being averaged out to 18% gray. The problem that a camera's meter has is that it can only read reflected light. In easier to understand lingo, it's only reading the light that is bouncing off of your subjects and making a guess at how much light is actually there. In a perfect world everything would bounce the same amount of light off and your camera's meter would not have a problem. A quick example, if you are taking a shot of a white bird in the snow, your shot is primarily white. The camera will take that metering and average it out to middle gray even though the image is primarily white. When this happens and you adjust the exposure for the camera's  recommended metering, your shot is going to be underexposed because it read the whites as grays!

In a different scenario if you are taking an image of a black cat against a black background, your camera is going to average out all those blacks to middle gray. When that happens and you adjust for your camera's exposure the image is going to be overexposed because it read the blacks as grays.

Don't worry if it doesn't make sense right now, it will!

The meter is located inside your camera's viewfinder. Depending on your camera make and model, the position of the meter will vary compared to the image above. But they all work the same! The meter looks like a bunch of tiny lines with a zero right in the middle and a + and - sign at either end. Depending on your camera, you might even have some 1's and 2's in it like the example below:

So now you know what the meter looks like but what is it doing? Well, when the camera meters a scene it takes calculations of the brightness of the light that is in the scene. The object of the metering game, because that's what it feels like sometimes, is to align the meter and put it on the 0. When the bar is aligned with the zero the camera is telling you that, in it's humble opinion, you have the proper exposure. You set the exposure using your Shutter Speed, Aperture or ISO! So when you have it all aligned, the combination of those three elements is correct. Unfortunately it's not always right. It's not always correct because of the variance of scenes and reflected light so to compensate we have different metering modes. The different metering modes are going to allow you to obtain the best exposure possible no matter what the situation is. It might not make sense right now, so let's go over the 3 most popular metering modes that are available on almost every camera.

Please note that the icons are different depending on the manufacturer of the camera, the names might vary as well but the way they work are all the same! In the above image, Matrix Metering is Nikon and Evaluative Metering is Canon! They also use different icons.

The 3 most common metering modes are:

1. Evaluative/Matrix Metering
2. Center Weighted Metering
3. Spot Metering

Each one of these metering modes will result in different exposures of the same scene, so it's best to know what all three do so that you know what to use and where!

Evaluative or Matrix Metering Modes

The Evaluative or Matrix Metering Mode is most likely what came setup as default in your camera. This after all is the most foolproof mode. 

In Evaluative or Matrix Metering Mode, the camera will take samples from all over your scene and average it out. (This is not a real representation of where your actual sample points are taken from, this is just to help you wrap your head around the concept). This is probably the scene that will give you the best results in every day situations. The problem will occur when it's an image like the one that is in the viewfinder, there is such a huge difference between the brights and the darks that the camera doesn't know what to do. It will make an average of the scene and try to expose properly for both. I highly recommend this mode when the light is even and the difference between shadows and highlights is not too dominant in the scene! I use this metering mode most of the time. I only change it out of this mode when the scene gets more complicated! 

Center Weighted Metering

The second most common metering mode is center weighted. To be honest, I rarely use this mode as I have yet to find a really good reason. But it's still good to know how it works!

The Center Weighted Metering Mode is kind of a hybrid mode, it's still metering from all the points all over your image, but the majority of the reading is being taken from the center. Now, again, this illustration is not exact, it's just so that you can wrap your head around it. I honestly have not found a situation where this is a logical choice, but your photography might be different than mine. I rarely frame my shots to where I need to know the exposure of the middle more than the outsides, but again yours can vary! 

Spot Metering Mode

Apart from Matrix/Evaluative Metering, Spot metering is my most used mode...I LOVE IT! Although I warn you it is a little more complicated to use!

 When you set your metering to spot, the camera will meter a small area of the frame. On most camera's it will meter wherever your autofocus point is! In the image above you see the camera metered for the bright sun which allowed me to expose correctly for the sky! It didn't take anything else into account, just where the autofocus point was. This mode gives you the ability to choose where the metering is being taken from. It's extremely effective when there is a complicated lighting scenario, like a backlit subject. I also love using this when I am shooting portraits because I can meter off the subjects skin giving me a perfect exposure. But you must be careful, because just like I stated above, if you are metering a white area of your shot, the camera's metering is going to read it as gray and underexpose your shot. Same goes if you are metering something that is black, the camera will turn it into gray and give you an overexposed image.

Spot metering takes a little getting used to, but with practice, I'm sure you're going to love it as much as I do!