  Direct state tomography (DST) using weak measurements has received wide
attention. Based on the concept of coupling-deformed pointer observables
presented by Zhang \emph{et al}.[Phys. Rev. A \textbf{93}, 032128 (2016)], a
modified direct state tomography (MDST) is proposed, examined, and compared
with other typical state tomography schemes. MDST has exact validity for
measurements of any strength. We identify the strength needed to attain the
highest efficiency level of MDST by using statistical theory. MDST is much more
efficient than DST in the sense that far fewer samples are needed to reach
DST's level of reconstruction accuracy. Moreover, MDST has no inherent bias
when compared to DST.
