Dispersion of the ratio L_IR/νL_ν as a function of wavelength in bins of redshift and for the five Herschel bands in the four CANDELS fields. The wavelength is normalized here to the “peak” wavelength, where the FIR SED in νL_ν reaches its maximum (calibrated from our stacked SEDs, Fig. 6). The L_IR is computed by fitting all the available Herschel bands (we require a minimum of three) together with CE01 templates, while νL_ν is the flux in a single Herschel band converted to rest-frame luminosity. Open symbols denote measurements where νL_ν comes from MIPS 24 μm. Error bars come from simple bootstrapping. The contribution of photometric errors was statistically removed. The red line shows a fit to the data points to guide the eye.