Extinction vs. distance diagram for the stars classified in the Vilnius system. Dots are the IC 1805 members, crosses are field stars. The three curves show the limiting magnitude effect for A0 V, A5 V, and F0 V stars at V = 17 mag. The crosses of absolute errors are plotted at d = 1 and 2 kpc, corresponding to the distance errors for ΔM_V =  ± 0.5 mag and the extinction errors ±0.15 mag.