Anisoplanatism effects in Shack-Hartmann Wave Front Sensing with Laser Guide Stars on the ELTs N. Muller, C. Robert, V. Michau, T. Fusco, C. Petit, J.-M. Conan, N. Vedrenne and G. Rousset Published online: 24 February 2010 DOI: 10.1051/ao4elt/201005015