How does a foresters prism work?
A prism works on light refraction. Light is distorted as it passes through the prism. This distortion causes objects that are viewed through the prism to be displaced toward the thin edge of the prism. The amount of displacement is related by a mathematical factor to basal area. A 10 factor prism is most common as it allows data collected from each sample point to be converted to an acre basis by multiplying by 10.
