A spot meter is a specialised light meter that measures exposure from a very narrow area, typically covering just a one-degree angle of view. This allows photographers to take highly precise light readings from a specific part of the scene rather than averaging the exposure across the entire frame.
Spot meters are particularly useful in high-contrast situations where accurate exposure of a key subject area is essential, such as portraiture, stage photography, or dramatic lighting conditions. Many advanced SLR and DSLR cameras feature built-in spot metering modes, with the metering area often indicated on the viewfinder screen, enabling photographers to carefully control exposure and achieve more accurate tonal results.