Top: TGAS parallaxes (π_TGAS) vs. HIPPARCOS parallaxes (π_Hip) to the five members of Chamaeleon I included in both HIPPARCOS catalog (van Leeuwen 2007) and TGAS catalog (Gaia Collaboration 2016a). The black line represents the one to one relation. Bottom: same for distances, taken as inverse of the parallax for HIPPARCOS data and from Astraatmadja & Bailer-Jones (2016) for TGAS (see Table 1). Uncertainties on both axes are as discussed in Table 1, and they correspond to 1σ uncertainty for the HIPPARCOS values and 2σ for TGAS.