Differences in radial-velocity shifts between lines with different strengths (but similar excitation potentials). These data at μ = 1 are from synthetic isolated Fe I lines at λ620 nm in the N58 model. Each point represents the difference between instantaneous radial velocities (e.g., strong line minus weak) at one temporal snapshot during the simulation. The straight lines are fits to the data points. The different scales between the frames are adapted to reflect how convective blueshifts deviate for lines with increasingly different strengths.