Examples of generated mock clusters with varying ages and extinctions on real background images. The masses of the clusters are log₁₀(M/M_⊙) = 4.5, their sizes are log 10(r_h/arcsec) = −0.7. The images are normalized as in Fig. 1. Top panel: clusters superimposed on a sparse background, bottom panel: same clusters superimposed on a denser background. The visibility value is indicated on the bottom left of each image. The sizes of the images are 64 × 64 pix.