Broad-band spectral energy distribution of the afterglow of GRB 080825B as observed with GROND. The foreground-corrected SED shows two prominent breaks corresponding to Lyman-limit absorption in the g′ band, and Lyman-α in r′. The corresponding redshift is . The inset shows the confidence contours of the redshift solution versus intrinsic extinction, where the three-dimensional parameter space has been collapsed onto a two-dimensional grid. The increasingly dark shaded areas correspond to the 68.3% (1σ), 90%, 95.4% (2σ), 99%, 99.73% (3σ) and 99.99% confidence contours, where the 68.3%, 90% and 99% contours are also marked with solid lines. The different filter bands are plotted with their effective wavelength, and the horizontal error bars represent their FWHM, i.e. from 50% to 50% of maximum transmission.