Knowing when to switch to spot metering can give you a big advantage when shooting in difficult lighting conditions. In this tutorial we’ll show you how to spot meter in these situations to achieve the most precise exposures possible.
Much of the time your digital camera’s auto-exposure system will do a perfectly good job. Your Evaluative metering mode breaks the scene down into different zones, analyses the light in each and tries to make a prediction about the subject and the lighting conditions.
However, it can get it wrong. This can happen where the camera doesn’t quite interpret the scene correctly or you’re photographing an intrinsically dark or light-toned subject. You can fix this by applying a little EV (exposure) compensation and retaking the shot.
There are other situations, though, where there’s more than one ‘correct’ exposure, depending on how you, the photographer, want the shot to look.
Here’s the perfect example. We’re shooting a portrait in a dark tunnel with a bright background, and we’re going for two completely different effects: a light and airy high-key portrait where the background is blown out, and a dark and moody low-key shot where we only see our subject as a profile in silhouette.
The camera can’t possibly know what style of shot we want. Left to its own devices, our camera will try to work out some kind of compromise exposure where there’s a bit of detail in both the subject and the background, but the difference in light levels is so great that it’s never going to work very well.
Let’s see what happens if we use spot metering instead. In this mode, you can take a meter reading from any area of the scene and use this as the basis of the exposure.
By choosing two different areas of the picture we can produce two very different effects, as you can see in our images at the top of this page.
A step-by-step guide to accurate spot metering: steps 1-3
On old-fashioned film cameras, spot meter readings were taken from the centre of the frame. If you expect your DSLR to work in the same way, you could end up with some very strange and unpredictable exposures indeed.
In fact, on some cameras the spot metering area is linked to the autofocus point. This means you have much more control over it… but you also need to be more careful.
01 Tunnel vision
Here’s our location. We’ve positioned Claire just inside the tunnel entrance where the light is much darker, but the background behind is very bright. A tripod will keep the camera still and Live View mode lets us position the autofocus/spot area with a great deal of precision.
02 Set spot mode
There are two steps when selecting spot mode. First, we need to set the camera to single-point AF mode (see the sidebar overleaf). Next, we select spot mode from our Nikon D5200’s interactive display. More advanced cameras have metering mode switches on the body.
03 AF point placement
For our high-key shot, all we need to do is place the AF point over Claire’s face. The autofocus area and spot metering mode are linked, so this is where the camera will take its meter reading. Claire’s face is perfectly exposed and the background is nicely blown out.
Histogram: photography cheat sheets for achieving perfect exposure
Expose to the right: the camera technique every landscape photographer must know
Creative spot metering: how professionals expose in high-contrast conditions
3 exposure techniques every beginner must know (and when you should use them)
Backlighting subjects: 4 advanced tips for dramatically lit photos