50 and 95% posterior limits for the estimated contamination in the i′ band for an M dwarf slightly contaminated by a G2 star (10% of the total flux) with or without an informative prior on ρ_⋆ and b (first two rows from the top and the last two rows from the top, respectively), and either informative or uninformative prior on T_Eff,H (first and third, and second and fourth rows, respectively). The results are shown for three impact parameters (b), three apparent radius ratios in the i′ band (k_app), three dataset sizes (n), and two transit durations, as detailed in Sect. 4.1. Blue colour corresponds to short (1 h) transit duration, and orange to long (2 h) transit duration.