Eleanor: I thoroughly enjoyed this lens. So much so, I extended my rental period. It focused quickly for the most part and yielded clear, sharp images. I was sorry to return it. I used it with either a monopod or tripod, though I think it possible to handhold if you're very good with that. The only drawback I found was the inability to zoom out to find the bird who flew out of view. (which is obvious being it's not a zoom lens-but something you want to consider depending on what you will be shooting). If you're photographing things you know will be far away, this lens is a good choice and one I will probably be renting again. And, Borrow Lenses is great!