As amateur photographers, once you have come to grips with ISO, aperture and shutter speed we find ourselves craving to learn more in order to take our photographs to the next level. There are so many technical terms, complicated theories and concepts that can often sound too daunting to deal with.
What I have found easier with photography is not to attempt to learn everything at the same time but rather to take it step by step. So, the technical term that I will be explaining today is metering. Most cameras will have some subset of the following metering modes: spot, center weighted average (sometimes just called “average”), evaluative (sometimes called multi-segment or matrix) and partial (not found on all cameras so won’t go into this one).
In this article, I explain each one of these in a way that I hope will help you take your wildlife photography to the next level.
Different metering modes measure the brightness of an image in different ways according to what your subject is and adjusting the exposure accordingly. Cameras all differ in how to change the metering mode and what symbols are used for each one but the general symbol to look out for is one that looks like an eye. For the sake of attempting to keep things as simple as possible, I have only shown examples on a Nikon D300 and a Canon 7D. I recommend a Google search or the information booklet that comes with your camera to help you find yours.
This is a Nikon D300 and you can see the dial on the AE-L/AF-L button. It has three positions: Center Weighted, the circle on the top, Matrix, the rectangle in the middle and Spot, the dot on the bottom. The Canon 7D is shown differently in each subsection below.
Spot metering is the easiest to understand: The camera meters only a small area in the center of the frame. This mode is useful if there is a particular area of the frame that you must expose properly, even if it comes at the expense of overexposing or underexposing the rest of the image. Spot metering can be tricky to use properly. If the metered area is quite small, tiny camera movements can have dramatic effects on the metering, making it tricky to get the desired exposure.
On the Canon 7D the metering is changed by pressing the (o)-WB button and dialling left or right according to what mode you are looking for – here you can see that the camera is on spot metering, shown in the form of the dot.
The TOP image of a goliath heron is a good example of how to use spot metering. I exposed for the heron as the background was a lot darker and I wanted to keep the detail in the subject. Canon 7D, 100-400mm, AV mode, 1/500th second, f/8.0, ISO 200. Photographed by Kate Neill
This is a perfect example on how to lock your exposure when using spot metering. In this shot, James used Spot metering with a centre focal point, composed with the leopard in the focal point, locked his exposure (pressing down on the *) and then recomposed and shot. This enabled him to get a perfect exposure on the leopard without allowing the light background to have an effect on the exposure. ISO 1000, f 4.0 1/640th 200 mm. Photographed by James Tyrrell.
Evaluative Metering (Matrix)
Evaluative metering is the most complex metering method, even though it is often the default on most cameras. It samples multiple areas of the frame and tries to come up with a good exposure value that takes all of these areas into account.
The camera will seperate what it sees into different zones and will expose according to these zones taking into consideration the focal point that you have chosen. With this being said, it is the most commonly used metering in wildlife photography and is often the default on most cameras. The best time to use evaluative metering is when your composition does not have too much difference in the lights and darks and you will find that the camera exposes perfectly. For wildlife photography, I suggest using this mode as your default setting.
Evaluative metering is shown as per the image above on a Canon 7D.
A close up view of the Vomba Young Male.
One of my favourite sightings. A flap-necked chameleon during the day.
Center-weighted average metering takes an average over the entire scene, where, as the name indicates, the average is weighted more heavily towards the centre. This implicitly makes the assumption that the centre is the most important part of the image, but that you don’t want to completely ignore the edges of the image either. Different to evaluative in that it does not use the focal point to take the exposure from but rather only uses the centre of the image, making every shot on centre weighted the same in terms of where the exposure is taken from. If implemented properly, this metering mode usually works pretty well. Moreover, with some practice, it will be relatively easy to predict when it will fail and to compensate. In wildlife photography this is the less popular of the different metering modes.
Center-Weighted Average metering is shown above as per a Canon 7D
For this photo of Tamboti female, settings were as follows: Shutter: 1/800sec; F4; ISO 400, Underexpose 2/3. I also used center-weighted metering. What this does is evaluate the average light around the centre of the image. The camera makes a decision on shutter speed based on the light over the entire image but focusing mainly on the centre. In cases such as this with very bright corners, it ensures that the face and body are still properly exposed. If not used, the face would be much darker as the camera would compensate for the bright background. Photographed by David Dampier
I hope that I have helped you to understand this concept. If you have any advice on how to use these metering modes that I haven’t mentioned then please feel free to let us know in the comments section below.
Written by Kate Neill
Photographed by James Tyrrell, Kate Neill and David Dampier