I'd like to get a telephoto new lens for my d3100, mostly for taking zoo/nature pics, and background blur for portraits. I get frustrated with the lack of zoom with the kit lens. Im looking to spend about $200, and would buy used if thats an option. I thought what I wanted was pretty simple, but after looking at the telephoto lenses ranging from 150-1000 I'm throughly confused. Also, with the d3100, do you have to get a motorized lens?