Axial segregation in metal-halide lamps is caused by a complex interaction between convection and diffusion and is not yet fully understood. By enhancing convection, by placing the lamp in a centrifuge, the effect of convection on axial segregation was studied. The centrifuge caused the lamp to be accelerated between 1g and 10g. Optical emission spectroscopy was performed on a metal-halide lamp while placed in the centrifuge. Several transitions of atomic and ionic Dy, and atomic Hg were measured at different lateral positions from which we obtained atomic and ionic Dy and atomic Hg intensity profiles. Atomic lateral profiles of Dy at different axial positions in the lamp were used for the calculation of Fischer's axial segregation parameter. The theoretical model of the Fischer curve, which shows the axial segregation parameter as a function of convection, was verified along the full range by measuring lamps of different fillings and geometry. Moreover, the radial temperature profile of the arc for the different accelerations was determined.