Surface Brightness Fluctuations: A Case for Extremely Large Telescopes

The Surface Brightness Fluctuations (SBF) Method for distance determinations of elliptical galaxies is been modeled in order to investigate the effect of the Point Spread Function (PSF). We developed a method to simulate observations of SBF of galaxies having various properties and located at different distances. We will use this method in order to test the accuracy on the estimates of the extra-galactic distances for PSFs representing typical seeing conditions, Adaptive Optics (AO) systems and for future observations with Extremely Large Telescopes (ELTs) close to the diffraction limit.