Hi! I've been following along here for a while, but this is my first time posting. The D3100 was my first DSLR and I've been using it for a few years now for portrait photography with a 50mm f/1.8 lens. I never use the video functions or the kit lens and I just feel that I'm ready for something better. My head is spinning with the forums about full sensors and crop sensors. I love my lens and I just want to buy a new, upgraded Nikon body but I don't know what to buy. What is the best Nikon body for portrait photography? If I am interested in the full sensor body will I have to buy a new lens?