A test artifact for a coordinate measuring machine includes a calibrated standard and a convex background illumination surface. The calibrated standard, the convex background illumination surface and a vision sensor are positionable relative to one another so as to create a silhouette of the calibrated sphere in the vision sensor's field of view. The test artifact may thus be used to calibrate the coordinate measuring machine, and/or to assess the associativity between the vision sensor and another measuring sensor.