I've brought a DSLR (Canon 5D and 24-105 zoom lens) to the game twice. Once for a Raider game in 2015, when I was wearing a Raider jersey, and I was told that I couldn't bring the camera into the stadium. I had to try two other gates before I found someone who would let me through. I think I was being discriminated against.
I also brought it to another game this year (2016) and wasn't wearing any "silver and black" (since the Raiders weren't playing) and had no problems bringing the camera in.
If you get turned away, just try another gate (and get there early!).