With spot metering, of course.
I never had to bother with it before, but in retrospect I really should have.
Oh, I know how much the camera meter likes 18% gray, but I didn’t think much of it. Matrix metering — a/k/a evaluative a/k/a zone metering — is the default setting on most cameras — and for a reason. It (generally) works.
Olympus cameras are a bit snobbish. Their matrix metering is called ESP, which stands for electro-selective patterning. Arrogance aside, I like this name. In any event, it works about the same as the other-named brands.
Matrix metering works by dividing the scene into zones (“patterns” in Olympus-speak).
It evaluates the light in each zone and then calculates what it thinks (if cameras could think, that is) is a proper exposure of the combination of lights and shadows.
It works great! as long as the zones don’t vary too much.
And if your subject pretty much fills the frame when you look through the viewfinder, you will absolutely love matrix metering!
So, as long as I could identify my subjects with a reasonable degree of certainty, I guessed I was safe in using matrix metering.
Matrix is fine when your subject fills (or nearly fills) the scene.But what if there are a lot of dark areas in your scene? and a lot of light areas as well? Averaging these into an overall 18% gray means you are going to lose either the dark shadows or the brighter areas. Which is why, by the way, you should be checking your histogram, but that’s another story.
In that case you will have to choose, guided by the histogram, which one to sacrifice, the lights or the darks.
Or you could choose center-weighted metering. The light meter will still evaluate all the zones, but the center zones will be given priority.
But what if your scene is full of contrasting lights and darks AND a big white blob in the center, which is going to fly away at any second?
That’s where spot metering reigns supreme.
In spot metering you point at a specific area, and the meter evaluates only the area you are pointing at.
And THAT, my friends, is why this delightfully leucistic red-tail hawk looks so delightful.