  I present the results of a new approach to the intensity and photon density
spectrum of the intergalactic background light as a function of redshift using
observational data obtained in many different wavelength bands from local to
deep galaxy surveys. This enables an empirical determination of both the EBL
and its observationally based uncertainties. Using these results one can place
68% confidence upper and lower limits on the opacity of the universe to
{\gamma}-rays, free of the theoretical assumptions that were needed for past
calculations. I compare our results with measurements of the extragalactic
background light, upper limits obtained from observations made by the Fermi
Gamma-ray Space Telescope, and new observationally based results from Fermi and
H.E.S.S. using recent analyses of blazar spectra.
