Source Imaging Goniophotometers

The SIG series from Radiant Imaging are state-of-the-art source imaging goniophotometers which are used to perform precise, near-field measurements of the luminance and colour versus angle from individual light sources (lamps, LEDs). This is the instrument that we use to generate the industry-standard Radiant Source Model files which are used in optical design and ray tracing.

SIGs are fully automated, computer-controlled goniometric systems that use a high resolution ProMetric imaging colorimeter or photometer to capture a precise model of a light source's near-field output. The image data and the Radiant Source Model (RSM) generated from it provide a complete and precise characterisation of the light source output that can be used for design evaluation and imported into any major optical design package to allow accurate design of lighting systems.

Depending upon the application requirements, either photopic, colorimetric, or spectral ray sets can be measured and generated. The generation of spectral ray sets is especially important for modeling wavelength dependent and refractive optics.

Several models of SIG are available to meet specific measurement requirements, The SIG-300 is designed for general light source measurement, while the SIG-310 is suitable for measuring larger light sources. The SIG-400 is optimised for LED measurement applications, while the SIG-500 is configured for testing those light sources that must be measured in a horizontal orientation.

The measurement data collected by a SIG is formatted as an RSM file, which contains all of the light source measurement information including the image data, so the measurement results can be reviewed in detail at any time. In addition, ray sets containing an arbitrary number of rays can be generated by ProSource software for export to other optical and illumination system design software packages such as ASAP, FRED, LightTools, LucidShape, Opticad, OSLO, SimuLux, SPEOS, TracePro, and Zemax, as well as generic file formats. Ray sets generated by ProSource from RSMs are more efficient than random Monte Carlo-generated ray sets as they contain equivalent information with only 20% of the number of rays. This results in faster optical design analysis times with higher accuracy.

SIG-300	SIG-310	SIG-400


The SIG-300 is a general-purpose near-field goniophotometer designed for measuring the near-field output of LEDs and other small light sources in both horizontal and vertical orientations, with sample sizes from 0.8-80mm. » More	The economically-priced SIG-310 provides measurements of sources from 6-400mm in both horizontal and vertical orientations, making it suitable for a wide variety of sample sizes, including complete luminaires. » More	The SIG-400 can measure a wide range of samples, from LED dies to complete luminaires with sizes from 0.6 to 225mm. The SIG-400 is constrained to measuring samples in a vertical orientation only. » More

SIG-500


The SIG-500 is a more affordable source imaging goniometer for those types of lamps whose orientation does not have to be fixed with respect to gravity. Samples of up to 400 x 400mm can be measured. Unlike other SIGs, the imaging photometer is separate and can be used for stand-alone measurements. » More