"The most logical option would be to send the camera through, but the electromagnetic field nukes the picture." -Quinn Mallory from Sliders
The fandom I was into before Marble Hornets was the 90's cult classic sci-fi series Sliders. It dealt with traveling, or "sliding", between different dimensions/parallel earths. The quote I included from the show ties into my theory about the Operator:
The Operator generates an electromagnetic field.
I can't believe I've never heard this theory before, because so much of it fits. According to Quinn, electromagnetic fields play hell with the picture on a camera, causing distortions and freezing and stuff. Does the Operator cause this? Check.
Is the Operator a being from another dimension? It's very possible. I consider "where there is no light" to be the Ark, the place where the Operator goes when he's not trolling the characters. It's basically a pocket dimension (as opposed to a parallel dimension) that he easily glides between,