Imaging Goniometers





Comprehensive view angle performance characterization system for large light sources

PM-NFMS (ProMetric Near-Field Measurement System) measures brightness, color, and, optionally, spectrum as a function of viewing angle for large light sources. It is designed to provide accurate luminance distribution data for developers of large light sources for automotive, transportation, architectural, and other applications. Because PM-NFMS captures a complete near-field model of the light source, it provides much more comprehensive information - in a much smaller measurement space - than can be obtained from traditional spotmeter-based measurements.


PM-NFMS generates illumination distribution data in multiple standard formats 

By processing the measured data, PM-NFMS can output IES format files, EULUMDAT files, illuminance distribution on a plane as table, and Radiant Source Model™ (RSM) files. The RSM files can be used to generate either photopic, colorimetric or spectral ray sets for use in optical design tools by using ProSource® Software.


PM-NFMS is a complete, automated system for large light source measurement and analysis 

The PM-NFMS system consists of a ProMetric® Imaging Colorimeter, a two-axis goniometer for precisely adjusting the display's angular position relative to the imaging colorimeter, and PM-NFMS software that controls both the imaging colorimeter and the goniometer during the measurement sequence. The PM-NFMS software also includes a comprehensive set of data analysis tools.

The PM-NFMS control and analysis software automates the measurement functions of both the ProMetric Imaging Colorimeter and the NFMS goniometer, allowing definition and execution of a complete measurement sequence with minimal effort. The measurement data is preserved as a set of display images, capturing an image of the light at each viewing angle as a Radiant Source Model (RSM). The RSM can be analyzed directly to understand light source performance, or Radiant's ProSource software can be used to convert the RSM to a ray set for use in leading optical design software packages.


Extensive analysis functions provide complete view angle performance analysis as well as extrapolation as an illumination distribution   

The PM-NFMS system software supports light source performance analysis through an extensive variety of quantitative analyses, including isoplots, CIE color analyses and radar plots. In addition, the PM-NFMS software can be used to extrapolate a far-field illumination distribution from the measured near-field RSM. Because the illumination distribution is derived from the near-field data, this results in a substantial reduction in the space required to perform these measurements when compared to spotmeter-based methods where the measurement instrument must be place in the far field. The spotmeter cannot provide near-field data either.


Multiple hardware configuration options fit any application 

Any ProMetric Imaging Colorimeter can be selected for use in the PM-NFMS system; the ultimate selection will be a function of the dynamic range, measurement resolution, and field-of-view required. The PM-NFMS goniometer is available in several sizes to support varying light source sizes, ranging from headlamps to architectural lighting systems.