An experimental method to characterize the relationship between aperture image and ray directions in microscope optics.

We propose a direct experimental method to calibrate the relationship between ray directions in object space and their positions in the aperture plane of a light field microscope. The calibration improves the interpretation of light field images, which contain information from both types of image planes, the field plane and the aperture plane of the ray path in the microscope. Our method is based on the diffraction of line gratings of known periodicities and provides accurate results with subpixel resolution. The method can be custom-tailored to most any optical configuration, including standard light microscopy setups, whenever correct mapping between ray parameters in the object/image plane and the aperture plane is needed.