SphereOptics introduced a new multi-exposure feature (also known as HDR or High Dynamic Range mode) for their I- and Y-Series ProMetric imaging photometers made by Radiant Vision Systems. Radiant Vision Systems, formerly known as Radiant Zemax, is well known for their ProMetric high performance imaging photometers and colorimeters (cameras which measure the amount and colour of light) which are widely used in the development and testing of flat panel displays, lighting, LEDs and in vehicle lighting applications.
The new HDR mode increases the dynamic range of the ProMetric camera significantly (up to 1,000,000:1). The newly developed algorithm achieves this range extension by com-bining separate images with different exposure times. This method increases the grey scale range of the image while at the same time as lowering the noise level. The accuracy of the measured luminance and colour remains very high, with a percentage error of +/- 3 % for luminance (cd/m²) and colour coordinates x, y of +/- 0,003.
The multi-exposure HDR feature allows for a more accurate luminance analysis of a device under test which features simultaneously both low and bright light illumination levels. A good example of an application which benefits from the HDR mode is the measurement of emergency signs when looking simultaneously at the sign and at the light pattern on the wall. Other examples are street lights and their pattern on the street or on the pavement, where the HDR mode allows for the measurement of the illumination pattern as well as the light emitted directly from the lamp.