The Red-Sequence Cluster Survey ( RCS ) is a 100 deg ^ { 2 } galaxy cluster survey designed to provide a large sample of optically selected clusters of galaxies with redshifts 0.1 < z < 1.4 .
The survey data are also useful for a variety of lensing studies .
Several strong lensing clusters have been discovered so far , and follow up observations are underway .
In these proceedings we present some of the first results of a weak lensing analysis based on \sim 24 deg ^ { 2 } of data .
We have detected the lensing signal induced by intervening large scale structure ( cosmic shear ) at high significance , and find \sigma _ { 8 } = 0.81 ^ { +0.14 } _ { -0.19 } ( 95 % confidence ; for a CDM cosmology with \Omega _ { m } = 0.3 ,~ { } \Omega _ { \Lambda } = 0.7 ,~ { } h = 0.7 ) .
Another application of these data is the study of the average properties of dark matter halos surrounding galaxies .
We study the lensing signal from intermediate redshift galaxies with 19.5 < R _ { C } < 21 using a parametrized mass model for the galaxy mass distribution .
The analysis yields a mass weighted velocity dispersion of \langle \sigma ^ { 2 } \rangle ^ { 1 / 2 } = 111 \pm 5 km/s .
In addition we have constrained for the first time the extent of dark matter halos , and find a robust upper limit for the truncation parameter s < 470 h ^ { -1 } kpc ( 99.7 % confidence ) .
The biasing properties of these galaxies as a function of scale are also studied .
The RCS data allow us to measure the ratio of the bias parameter b and the galaxy-mass cross-correlation coefficient r .
The results are consistent with a scale-independent value of b / r , for which we find b / r = 1.05 ^ { +0.12 } _ { -0.10 } ( for a \Lambda CDM cosmology ) .