<p>I will leave you guys to debate how legit the photograph is below. To my eyes, it looks pretty good.</p>
TLDR: That is not a photograph!
If it's not blindingly obvious to you that this is a 3D rendering, your eyes need checking. And it's not even a particularly good 3D rendering either, with absolutely no surface texture to speak of. I'm not saying it isn't an official press picture created by Sigma, but it's pretty embarrassing for a photography website to mistake an artificial drawing for a photograph.
Hahahaha. It is real dude. You just embarrassed yourself!