Comparison of the synthetic spectrum of Wd1-30a derived from the optimised model-atmosphere solution described in Sect. 4 (red) to observational data (black). A further R-band spectrum is overplotted (orange) to demonstrate the night to night variability of the Hα profile (spectra from 2004 June 12 and 13). The units of wavelength for the top and middle panels are Angstroms and the bottom panel microns.