We use galaxy surface brightness as prior information to improve photometric
redshift (photo-z) estimation. We apply our template-based photo-z method to
imaging data from the ground-based VVDS survey and the space-based GOODS field
from HST, and use spectroscopic redshifts to test our photometric redshifts for
different galaxy types and redshifts. We find that the surface brightness prior
eliminates a large fraction of outliers by lifting the degeneracy between the
Lyman and 4000 Angstrom breaks. Bias and scatter are improved by about a factor
of 2 with the prior for both the ground and space data. Ongoing and planned
surveys from the ground and space will benefit, provided that care is taken in
measurements of galaxy sizes and in the application of the prior. We discuss
the image quality and signal-to-noise requirements that enable the surface
brightness prior to be successfully applied.Comment: 15 pages, 13 figures, matches published versio