Whisker plot (left column) and the complex ellipticities (right column) obtained from the PSF parameters for the 022539-041200 tile in the i-band. The upper panels show the results obtained from uncorrected star ellipticities, the middle panels – from the 2D polynomial approximation of the Moffat parameters and the bottom panels – the final results after the correction for the anisotropy was applied. The small bar at the left-bottom corner of all left panels shows the ellipticity e = 0.1. Apparent i magnitudes are marked by colours given in the vertical colour bar: values of 18–19 mag by red, values of 19–20 mag by green, values of 20–21 mag by blue, and values of 21–22 mag by orange.