PDF of column density for the Corona Australis cloud. The solid red curve represents the best-fit of a single log-normal distribution to the data. The residuals of the fit are presented in the lower panel. The grey area in the residual plot delimits what would be expected from poisson noise. Note that the residuals are not poissonian but exhibit a clear pattern. The excess over the log-normal fit on the high extinction tail is present in a similar manner to the results for the clouds in Papers III and IV, and the results of Kainulainen et al. (2009) and Froebrich & Rowles (2010).