Spectral response for the Planck/HFI 545 and 857 GHz filters (red) and the Herschel/SPIRE PLW and PMW filters (blue), respectively, each normalized relative to a maximum at unity. For SPIRE these include the spectral dependence of the beam across the band as is appropriate for extended emission (compare Figs. 5.16 to 5.5 in the SPIRE Handbook v2.5). No correction is needed for HFI.