Dereddened KLFs (see text) for sources in the H − K_s colour interval corresponding to a reddening interval 3.2 <A_V< 7.8 (see text) from the mean locus (pseudo-sequence) of young stars. From bottom up: sample selected from the southern field only (pseudo-sequence at 1.7 kpc), from the whole SofI field (pseudo-sequence at 1.7 kpc), and from the whole SofI field (using a pseudo-sequence shifted to a distance of 2.56 kpc). The KLF at the top has been obtained for sources with A_V> 7.8 mag picked from the whole field (pseudo-sequence at 1.7 kpc). The two vertical dotted lines mark the completeness limit for the KLF at the top (K_s = 13) and that for the other three KLFs (K_s = 15).