Monitoring of imaging performance is well-established and the subject of both imaging standards and guidelines for cultural heritage institutions. To date emphasis has been on the imaging of flat object. As more three-dimensional content is being captured though, performance metrics for this class of materials need to be introduced and considered. Chief among these is depth-of-field (DOF), the distance of acceptable focus along the optical axis in front of the lens. We propose adapting image-resolution tools for arriving at a practical method for measuring depth-of-field. We discuss requirements for test-chart objects and analysis software.