We present a spectroscopic analysis of two galaxy clusters at z \approx 0.2 , out to \sim 4 Mpc .
The two clusters VMF73 and VMF74 as identified by ( ) were observed with multiple object spectroscopy using MOSCA at the Calar Alto 3.5 m telescope .
Both clusters lie in the ROSAT Position Sensitive Proportional Counter field R285 and were selected from the X-ray Dark Cluster Survey ( ) that provides optical V - and I -band data .
VMF73 and VMF74 are located at respective redshifts of z = 0.25 and z = 0.18 with velocity dispersions of 671 km s ^ { -1 } and 442 km s ^ { -1 } , respectively .
Both cluster velocity dispersions are consistent with Gaussians .
The spectroscopic observations reach out to \sim 2.5 virial radii .
Line strength measurements of the emission lines H _ { \alpha } and [ O II ] \lambda 3727 are used to assess the star formation activity of cluster galaxies which show radial and density dependences .
The mean and median of both line strength distributions as well as the fraction of star forming galaxies increase with increasing clustercentric distance and decreasing local galaxy density .
Except for two galaxies with strong H _ { \alpha } and [ O II ] emission , all of the cluster galaxies are normal star forming or passive galaxies .
Our results are consistent with other studies that show the truncation in star formation occurs far from the cluster centre .