My Voigtlander Nokton 58mm f1.4 SLII is, by far, the sharpest lens I have ever owned.
At its optimum aperture of F5.6, no further sharpening during PP can be done, as it begins to form sharpening halos! I did a studio shoot about a couple of months ago and I stuck with the Voigt for shoulder shots and the DA40/2.8 for complete body shots. The DA40/2.8 could accept further sharpening during PP, but not the Voigt! What came out from the camera was what was used.
Oh, and the Voigt is likewise the sharpest lens I have ever owned when shot wide open