Is the sigma 15mm f 1 4 dg dn diagonal fisheye art sharp wide open?

The page for the Sigma 15mm f/1.4 DG DN Diagonal Fisheye Art doesn't say how sharp it is at f/1.4, so I can't give you a straight answer from here. What it does cover: it's a full-frame fisheye for Sony E and L-Mount, made with night-sky photography in mind, and it frames like 22mm on APS-C.

On the aperture side, f/1.4 gives very thin depth of field. Stopping down a little is a good way to get more of a subject in focus, as the portraits guide explains. For how aperture affects light and blur in general, see the lenses guide.

For real sharpness results, look at independent tests of this lens, which will show corner and centre performance wide open.

Written by Claude from this site's pages.