  We present a deep wide field Halpha imaging survey of the central regions of
the two nearby clusters of galaxies Coma and Abell1367, taken with the WFC at
the INT2.5m telescope. We determine for the first time the Schechter parameters
of the Halpha luminosity function (LF) of cluster galaxies. The Halpha LFs of
Abell1367 and Coma are compared with each other and with that of Virgo,
estimated using the B band LF by Sandage et al. (1985) and a L(Halpha) vs M_B
relation. Typical parameters of phi^* ~ 10^0.00+-0.07 Mpc^-3, L^* ~ 10^41.25+-
0.05 erg sec^-1 and alpha ~ -0.70+-0.10 are found for the three clusters. The
best fitting parameters of the cluster LFs differ from those found for field
galaxies, showing flatter slopes and lower scaling luminosities L^*. Since,
however, our Halpha survey is significantly deeper than those of field
galaxies, this result must be confirmed on similarly deep measurements of field
galaxies. By computing the total SFR per unit volume of cluster galaxies, and
taking into account the cluster density in the local Universe, we estimate that
the contribution of clusters like Coma and Abell1367 is approximately 0.25% of
the SFR per unit volume of the local Universe.
