The fundamental matrix of a pair of pinhole cameras lies at the core of many systems that reconstruct 3D scenes from 2D images. However, for more than two cameras, the relations between the various fundamental matrices of camera pairs are not yet completely understood. In joint work with Viktor Korotynskiy, Anton Leykin, and Tomas Pajdla, we characterize all polynomial constraints that hold vanishing for an arbitrary triple of fundamental matrices. Unlike most constraints in previous works, our constraints hold independently of the relative scaling of of the fundamental matrices, which is unknown in practice. We also provide a partial characterization for essential matrix triples arising from calibrated cameras.