Video Photometer Accurately Measures Absolute Brightness

The Model 822 12-bit video photometer measures the absolute brightness of any size sample or scene and provides quantitative data in footlamberts (fL) or candela per square meter (cd/m²). It is used to measure the performance of such products as displays, lamps, LEDs, backlit panels, and control switches. It also quantifies reflectance, luminance, contrast, viewing angle performance, flatness, haze, and other appearance characteristics.
The 822 generates a 1,024 x 1,024-pixel image with a digitized 4,096 gray scale. It uses the company's Eyeppearance 12 Windows-compatible software to establish photometric levels for each pixel of a measured image. According to the company, the real potential of the software is realized when a calibration transform file is loaded for the image. The transform translates the relative gray levels into absolute radiometric levels. The system includes a variety of components including CCD camera, cable, photopic filter with one set of calibration curves, tabletop tripod, image processing board, and the Eyeppearance software.