The reconstruction properties of thin phase holograms of diffuse objects with large reference–object irradiance ratios are investigated, using the statistical method proposed by Goodman and Knight [ J. Opt. Soc. Am.58, 1276 ( 1968)]. Three types of phase-recording characteristics are treated: the linear-phase characteristic (the phase modulation being proportional to exposure), a nonlinear-phase characteristic, and the binary characteristic. For the maximum reconstruction efficiency of one of the ideal twin images, we obtain 18.4% for the linear-phase hologram and 31.8% for the binary-phase hologram.