Spot metering is most useful when your main subject is very different in brightness from the rest of the scene and you want exposure based on that specific area rather than the whole frame. Typical examples include sunsets, shaded subjects in bright surroundings, and the moon.

A spot meter reads only a very small part of the frame, so it helps when matrix metering would be fooled by strong contrast. It’s also useful when there’s a specific tone you want to place correctly, such as something that should look white or black.

Important: the meter assumes the area you meter should render as a midtone (about 18% gray). So:

• If you meter from a midtone subject, the suggested exposure is often close.
• If you meter from something white, add exposure (often around 1.5–2 stops).
• If you meter from something black, reduce exposure by a similar amount.

Because of this, spot metering works best when the subject is still or slow-moving, and many photographers prefer to use it with manual exposure so the reading stays consistent while recomposing.