Variation of the parameters of a log-normal fit to the PDFs of noise-contaminated maps as a function of noise amplitude and the width of the original cloud PDF. The upper plot shows the measured location of the PDF center, the lower plot the width of the log-normal fit. Without noise contamination η_center = η_peak = 0 and the measured width matches the PDF width of the cloud, σ_{log − normal} = σ_cloud.