High energy photon emission accompanying the spontaneous fission of Cf-252 is measured for different mass splits. The photon yields up to an energy of 20 MeV are obtained at several angles relative to the fission direction. Statistical model calculations are used to interpret the data. The photon yield is found to be very sensitive to the initial excitation energy sharing among the daughter nuclei and to their level density parameters. Using experimentally extracted level densities obtained from neutron evaporation measurements, the photon yield is well described by calculations for all mass splits.