Three spin estimations with slimbb assuming a 10 M_⊙ black hole in LMC X-3. Different alpha parameters and color correction treatments lead to a variety of trends with luminosity. The top two sets of fits have a low viscosity parameter, α = 0.01. The upper of the two (black circles) represents a fit using a constant hardening factor. The middle pattern (gray triangles) shows a fit obtained using f_hard calculated with BHSPEC. The bottom points (turquoise diamonds) result from a high viscosity parameter, α = 0.1, with BHSPEC hardening.