Is the sigma 105mm f 1 4 dg hsm art sharp wide open?

I don't have test results on this lens, so I can't tell you how sharp it is at f/1.4. What the page does say is that it's a very large, very heavy portrait prime known for its background blur. Its catalogue page lists the cameras it fits, and on full frame it frames as a true 105mm.

Be aware that at f/1.4 the depth of field can be thinner than a face, so one eye may be sharp while the nose or ear is soft. If you're shooting two people at different distances, stop down to about f/2.8. The portraits guide covers this in more detail, and the lenses guide explains what the f-number does.

Written by Claude from this site's pages.