• close distance, ideal for scanning large surfaces quickly.
• Narrow-Angle Lenses (e.g., 13°): Provide a much smaller FOV, allowing you to measure smaller targets from much farther away. These lenses offer better Spatial Resolution (the ability to see small details).

Spot Size Ratio (SSR) and Distance Measurement

This is perhaps the most crucial concept related to the lens. The SSR defines the ratio between the distance to the target and the smallest spot size the detector can accurately measure.