I recently read a blog post from a pretty competent photographer who said that there is no reason to use spot metering. Spot metering is where the camera determines a proper exposure not on the average brightness levels of the whole frame, but just of one specific spot. This photographer, like me, is principally a landscape photographer. Admittedly, I have never felt the need to use spot metering in my landscape work but it is extremely useful for shooting portraits. Let's learn why….
While I'm sure landscape photographers could find some use for spot metering occasionally, we're usually working our hardest to get everything in the scene properly exposed. It drives us crazy when we can't get the sky properly exposed. Portrait photographers, on the other hand, often let the background blow out into white so they can properly expose the model. Spot metering is perfect for this situation because it tells the camera not to be tricked into trying to find an average of the whole frame's brightness levels, but instead to only pay attention to the model's brightness levels.
The image featured on this page is a perfect example of spot metering. If evaluative or matrix metering were used for this shot, the model's face would be darker and muddier looking because the camera would have averaged out the whole scene, which is pretty bright.
The bright look in photos has become quite popular in portraiture lately. Nearly every engagement photo I see these days is of the couple standing there holding hands with the sun and sky over exposed behind the couple. I like this technique because it always makes the photo look clean.