I tried to make a realism tag but I couldnt find any tuts -.- so it didnt turn out great. Still open for c&c though Some lightning edit: v3:
One....if it is a realism tag I have no idea why he would have to color match it. Two, the render is sort of not fitting the background. The background looks too real for the render.
Render is too contrasted compared to the very soft background, main reason it's not fitting in perfectly, specifically his gun arm with that solid black area.