Establishing the performance of low-cost Lytro cameras for 3D coordinate geometry measurements

Lytro cameras are equipped to capture 3D information in one exposure without the need for structured illumination, allowing greyscale depth maps of the captured image to be created using the Lytro desktop software. These consumer-grade light-field cameras (Lytro) provide a cost-effective method of measuring the depth of multiple objects which is suitable for many applications. But, the greyscale depth maps generated using the Lytro cameras are in relative depth scale and hence not suitable for engineering applications where absolute depth is essential. In this research, camera control variables, environmental sensitivity, depth distortion characteristics, and the effective working range of first- and second-generation Lytro cameras were evaluated. In addition, a depth measuring technique to deliver 3D output depth maps represented in SI units (metres) is discussed in detail exhibiting the suitability of consumer-grade Lytro cameras suitability in metrological applications without significant modifications.