I've been browsing Nikon's website as well as forums trying to learn about what kind of lenses are available, and what kind of situations they are designed to shoot. I've got two questions. First, why do lenses have overlapping zoom ranges (for example Nikon makes 16-85mm and 17-55mm standard zoom lenses). Second, what type of lenses are optimal for casual outdoor photoshoots where the subjects are at fairly close range? Thanks! If I need to provide more information, just let me know.