Breaking Free of "The Matrix" (Metering, That Is)
"This is your last chance, Neo. After this, there is no going back. You take the blue pill and the PhotoTip ends. You wake in your bed and believe whatever you want to believe. You take the red pill and you stay in Wonderland and I show you how deep the rabbit-hole goes. Remember that all I am offering is the truth about matrix metering...."
-- with apologies to Laurence Fishburne's character Morpheus in "The Matrix"
In the popular movie staring Keanu Reeves, we learn that the Matrix prevents us from being aware of reality. When first introduced to the "real world," Neo (Keanu Reeves) has a hard time adjusting but eventually becomes master of his new circumstances. It occurred to me recently that this pretty much sums up many photographers experience with matrix metering as well. At first most photographers are completely happy with matrix metering, unaware or uncaring of any alternatives. Eventually they decide to explore the alternative to The Matrix and begin to feel like Alice having fallen down the rabbit hole.
As a place to start, let's look at why matrix metering is not your best choice if you want to be in control of your images. The theory of matrix metering sounds helpful enough: most Nikon bodies use a five segment matrix meter to measure brightness across the frame while the F5 takes this one step further and uses a 1005 segment meter. The camera then compares these results to an internal program based on evaluating some 30,000 images of varying kinds in order to determine the "overall" exposure. As such, it attempts to take into account subject brightness and other variables to figure out what it thinks is proper exposure. Many debate whether or not it can tell that the foreground is covered in snow and compensate for this as well, but suffice it to say, the camera is making decisions as to what it thinks is important that may or may not match what you think is important in terms of exposure. Based on past experience, you can then find yourself trying to use the Exposure Compensation control to remedy situations you think the meter needs a little help with. Unfortunately, this can become a vicious circle since you never really know what decisions the camera has made for you and what it hasn't. Coupled with Program Mode, the camera can now be on complete auto-pilot in terms of exposure. It's doubtful whether it really can do better than you though, if you take the time to learn how. In fact, fighting with your camera to gain control of exposure can be a rather frustrating experience.
My advice to you? Take the red pill and learn to meter for yourself instead of believing that matrix metering will solve all your problems.
There are two basic alternatives: center-weighted and spot metering. For the ultimate in control, spot-metering is the way to go. I won't talk too much about center-weighted but spot metering is the topic of next week's tip. While the sequel to the movie "The Matrix" is not due in theaters until later this year, your wait for the sequel to this tip will therefore be much shorter.