Low-beam headlamp illumination at very high angles

Abstract

This study was designed to provide photometric information for very high angles for a sample of U.S. low beams of recent vintage. The sample included 24 pairs of left and right lamps for 1999 and 2000 model year vehicles. The lamps were photometered in 0.2° steps from 10° up to 90° up, and from 60° left to 60° right. The report documents both the median and maximum luminous intensities at each test point. The utility of the present data is discussed in relation to retroreflective traffic signs, and veiling luminance in adverse weather such as fog.