Estimation of the possible bond of the close companions to KOIs detected in both i and z filters during the 2012 and 2013 observing seasons (see Sect. 4.2.2). The primary sources are represented in red and the close companions in blue. The solid black line represents the empirical ZAMS obtained by using the synthetic iz photometry from Ofek (2008) as grey dots, the observed members of the Pleiades cluster by Moraux et al. (2003) as purple circles, and Bouy et al. (2013) as green circles.