was calibrated using pixel scales of 12.267$\pm$0.009 and 12.263$\pm$0.009 mas/pix for the $K1$ and $K2$ filters respectively, and a [north]{} angle offset of $-1.712$$\pm$0.063$^{\circ}$[^6] [@Maire2016b].

We finally used TLOCI [to derive]{} the S/N maps for point sources. Each pixel value was divided by the standard deviation of the flux measured in [an annulus of 1 FWHM]{} at the same angular separation. The TLOCI throughput was assessed using synthetic companions inserted at regular separations between 0.15$''$ and 6$''$. We iterated the TLOCI analysis on several position angles to average the effects of random speckle residuals. The azimuthally averaged contrast curves discussed in Sect. \[sec:detectionlimits\] were estimated from these S/N maps. [We note that although the disk signal is strongly attenuated by the TLOCI algorithm (which was optimized for point-source detection) in the SPHERE and NaCo data (the latter are described in Sect. \[sec:nacodata\]), the disk residuals increase somewhat the measured noise level. This effect is stronger in the SPHERE data, because of the higher S/N detection of the disk. However, these effects are intrinsic to the data and do not have to be corrected for.]{} [Finally, we corrected the SPHERE detection limits for the coronagraph transmission radial profile (A. Boccaletti, priv. 