We analyze a sample of 105 clusters having virial mass homogeneously estimated and for which galaxy magnitudes are available with a well-deÐned high degree of completeness. In particular, we consider a subsample of 89 clusters with galaxy magnitudes taken from the COSMOS/UKST B j -band Southern Sky Object Catalog. After suitable magnitude corrections and uniform conversions to band, B j we compute cluster luminosities within several clustercentric distances, 0.5, 1.0, 1.5 h~1 Mpc and L Bj within the virialization radiusIn particular, we use the luminosity function and background counts R vir . estimated by Lumsden et al. on the Edinburgh/Durham Southern Galaxy Catalog, which is the wellcalibrated part of the COSMOS catalog. We analyze the e †ect of several uncertainties connected to photometric data, fore/background removal, and extrapolation below the completeness limit of the photometry, in order to assess the robustness of our cluster luminosity estimates. We draw our results on the relations between luminosity and dynamical quantities from the COSMOS sample by considering mass and luminosities determined within the virialization radius. We Ðnd a very good correlation between cluster luminosity, and galaxy velocity dispersion, with Our estimate of
. the typical value for the mass-to-light ratio isWe do not Ðnd any correlation ofwith cluster morphologies, i.e., Rood-Sastry and Bautz-Morgan types, and only a weak signiÐcant M/L Bj correlation with cluster richness. We Ðnd that mass has a slight, but signiÐcant, tendency to increase faster than the luminosity does,We verify the robustness of this relation against a number M P L Bj 1.2h1.3. of possible systematics. We verify that this increasing trend of M/L with cluster mass cannot be entirely due to a higher spiral fraction in poorer clusters, thus suggesting that a similar result would also be found by using R-band galaxy magnitudes.