SIG-400: Source Imaging Goniometer
SIG-400 Connectivity
SIG-400 Measurement Image
SIG-400: Source Imaging Goniometer
SIG-400 Connectivity
SIG-400 Measurement Image

Precise measurement of near-field luminous intensity for LEDs and other small light sources.

The SIG-400 (Source Imaging Goniometer®, Gen. 4) is a fully-automated, computer-controlled goniometric system designed specifically to meet the needs of LED researchers, developers, manufacturers, and users for LED die and device characterization. The SIG-400 uses a ProMetric® I Imaging Colorimeter to generate highly-accurate near-field models of LEDs. This data can be used directly to investigate the performance of the LED, or it can be exported using Radiant Vision Systems ProSource® Software, for use in all major optical design software packages.

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Efficiency and Cost Savings

Focusing on LED measurement needs

The SIG-400 is Radiant's fourth generation of the Source Imaging Goniometer and the realization of over 15 years of experience in light source measurement. By combining Radiant's latest advances in imaging colorimetry, robust mechanical design (to provide absolute accuracy), and easy-to-use control software, the SIG-400 can be readily applied to a broad range of measurement applications. By focusing on the needs of LED measurement, the SIG-400 is also very cost-effective.

The SIG-400 captures and aggregates images and flux measurements from thousands of angular viewpoints around a light source to precisely characterize the source's near-field output. The SIG-400 supports measurement of vertically-oriented light sources and can be ordered with both microscope and extended field-of-view optics, thus providing the flexibility to measure both LEDs and other light sources.

Complete Turnkey System

Generating accurate input for optical design

The SIG-400 system consists of a ProMetric® Imaging Colorimeter, a goniometric assembly for positioning the imaging colorimeter and the light source relative to one another, and SIG 2.0 Control and Analysis Software. The SIG-400 captures images of the light source from multiple angles, building a 3-dimensional spatial image of the color and luminance output of the light source. These measurements are aggregated into a Radiant Source Model™ (RSM) format, which is a detailed, industry-standard model for representing a light source's near-field data. RSMs contain all of the measurement information, including the image data, enabling measurement results to be reviewed in detail at any time. RSMs are used to compare the optical properties and designs of various LEDs and to generate input to the most common optical design software packages for use in luminaire and optical system design.

Applying Radiant's ProSource Software to the RSM, ray sets containing an arbitrary number of rays can be generated for export to other optical and illumination system design software packages such as ASAP®, FRED®, LightTools®, LucidShape®, Photopia™, IES TM-25, Opticad®, OSLO®, SimuLux®, SPEOS®, TracePro®, and OpticStudio™ (ZEMAX), as well as general file formats. Because the RSM is a complete description of the light source, it can be used to generate and regenerate ray sets at will. This provides smaller numbers of rays for rough design and a large number of rays for final design, making the overall design process more efficient.

SIG-400 Software

Current Version:

Ver. 2.3.11

Supported Products:

System Requirements:

  • 3.0 GHz and 8 cores
  • 16-32 GB RAM
  • Windows® 7 ot 10, 64 bit
  • Ethernet 100/1000 or USB 2.0

 Optical Specifications and Capabilities

Sensor Type CCD, Temperature Stabilized, Cooled to +5° C
System Dynamic Range > 60 dB
Resolution 600 x 600  1081 x 1081
Standard Field of View (FOV) 2.3 mm, 4.7 mm, 9.1 mm, 
13 mm, 25 mm and 54 mm
4.9 mm, 10 mm, 20 mm, 28.7 mm,
57 mm and 122 mm
Extended FOV: Micro 
(with SIG-400MF20 option)
0.6 mm 1.3 mm
Extended FOV: Micro
(with SIG-400MF10 option)
1.1 mm 2.4 mm
SIG-400EF option 98 mm 212 mm
Color Measurement* CIE 1931 matched XYZ filters 
Neutral Density Filters ND 0, 1, 2, 3, 4, and 5 standard
Measurement Capability Luminance, luminous intensity
Color: CCT; CIE x,y; u’,v’; DE

* Photopic-only option available for purchase

Mechanical Specifications

Overall Size 71 cm x 56 cm x 125 cm
Operating Footprint 74 cm x 127 cm
Azimuth Motion 0° to 360°
Inclination ± 140°
Angular Step Size 0.10° minimum for both azimuth motion and inclination
Run Out ± 0.015 mm mechanical-optical-software run out
Weight 130 kg
Construction Welded steel frame for thermal stability and rigidity

Control and Analysis Software Features

SIG Software
  • Automated motion and image capture control
  • Scan set-up checklist with direct links for ease of use
  • Completely configurable scan resolution 
  • Real-time, on-screen luminance image display, with playback option 
  • Record ambient alignment images, operating conditions, and product info for sample 
  • Generate Near Field and Far Field luminous intensity distribution
  • Data visualization tools: cross section, 2D isoplot, 3D isoplot, CIE color chart plot 
ProSource® Software
  • Generate illuminance on a plane for user-entered plane distance 
  • Create IES and ELUMDAT files 
  • Generate rays for import into optical design software


Specifications subject to change without notice.

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