The new optoNCDT confocal chromatic sensor from Micro-Epsilon combines the benefits of two successful confocal design concepts. With an external diameter of 8 mm, the sensor is compact and slim, similar to the optoNCDT 2402 range of miniature sensors. However, due to its larger digital aperture, the sensor can receive significantly more reflected light than the smaller, 4 mm diameter version. In the new sensor an ancillary lens is positioned in the light path before the thin gradient index lens with its exactly adapted refractive index profile. Due to its greater divergence, the so-called relay lens enables significantly more reflected light from the target to be detected. This is particularly beneficial if the sensor has to be tilted or if the target is nonplanar, so that the reflected light is only reflected back by an angular deviation in the sensor.