advantage of the LRG selection is that it does not depend upon the details of finding clusters of galaxies, and therefore, their selection is more straightforward to model (see Eisenstein et al. 2001).

Due to the 45 minute spectroscopic exposure time of the SDSS, the SDSS only targets LRG candidates brighter than r$=19.5$ (Eisenstein et al. 2001). This corresponds to a cut–off at $z\simeq 0.45$, but one can easily detect LRG candidates in the SDSS photometric data to higher redshifts$\footnote{Beyond z=0.45, the SDSS LRG selection
becomes easier than at lower redshift (with less contamination)
because of the fortuitous design of the SDSS filter system, see
Eisenstein et al. (2001)}$. Therefore, using the unique 2dF multi-object spectrograph on the Anglo-Australian Telescope, we have begun a joint SDSS–2dF program to push the original SDSS LRG selection to higher redshift. At the time of writing, our initial observations have been very successful, with spectra for $\simeq1000$ LRGs in the redshift range of $0.4 < z < 0.7$. In Figure \[2df\], I show the distribution in luminosity and redshift of these new SDSS–2dF LRGs and highlight that they cover a comparable range in their luminosities as the low redshift LRGs. By the end of 