Results of UPMASK on a simulated cluster with 10³M_⊙ and 10^9.5 yr at 1.5 kpc. In a) and b) we plot the distribution of field+cluster stars in positional space and in V vs. (B − V) space. In c) and d) we show the distributions of cluster members only. In e) and f) we plot the distributions of the cluster members identified by UPMASK. Dot size and transparency encode membership probability.