Hey all! I am currently interning at a car shop that wants some behind the scene shots. I am currently shooting with my Nikon D3200, and my 18-50mm lens. I'm having trouble with getting rid of the grain. I have bumped my ISO up to 800-1600, with an f-stop of 4.5, and I think a shutter of 1/30 to 1/60. Could it be my lens? Should I bump up to my 70-200mm? Or should I opt for a body change, like a D800 or D7100. Thanks!