Is the sigma 50mm f 1 2 dg dn art sharp wide open?

I don't have test results for how sharp this lens is at f/1.2, so I can't give you a verdict on wide-open sharpness. What the lens page does tell you: it's a 50mm f/1.2 prime for full frame, with Sony E and L-Mount versions, autofocus, and no stabilisation. On APS-C it frames like 75mm. You can see the full spec list and camera compatibility on the Sigma 50mm f/1.2 DG DN Art page.

If you want to know what f/1.2 is good for, the Portraits guide explains how wide apertures trade background blur against depth of field. For a sharper-at-f/2.8 mindset, that same guide suggests stopping down when two people sit at different distances.

Written by Claude from this site's pages.