Notes. Kerr and dilaton balck hole event horizon (EH), equatorial photon sphere (PS), and innermost stable circular orbit (ISCO). The right column lists the dilaton parameter in relation to the Kerr spin a required to have the two black hole systems matched at the respective radius. Parameters B, C, Z₁, Z₂, and σ are reported in Appendix A. All expressions are taken from the supplemental material from Mizuno et al. (2018).