Comparison of sSFR estimate inside the SDSS 3″ fibre. On the x-axis, we show the sSFR estimated from extinction corrected Hα luminosities (SFR_Hα), and on the y-axis, we show the sSFR inside the fibre (SFR_fibre) estimated by Brinchmann et al. (2004). The DP sample is marked with red circles, and the galaxies with an S/N > 10 in the Hα line of the RCSED catalogue (Chilingarian et al. 2017) are marked with black contour lines. We also show the median of groups of different gas extinction E(B − V), computed following Eq. (11), with solid thick lines. The black dashed line denotes SFR_Hα = SFR_fibre. The black error bar is the mean estimated uncertainty of the SFR, including stellar mass uncertainties.