Canon EF 100-400mm f/4.5-5.6L IS II USM Telephoto Zoom Lens - International Version (No Warranty) for Wildlife, Sports & Travel Photography

I'd been toying with getting this lens for quite a while and finally bit the bullet - and wow, am I happy I did. It hits the sweet spot for wildlife photography and I suspect will do the same for volcano shots as well. :)One feature that I've not seen mentioned that's a true joy for me is the placement of the focus ring. When shooting handheld, it's right under my left thumb, making it extremely easy to adjust focus on the fly. This makes a huge difference when in situations that are often too challenging for autofocus, like low-contrast shots or cluttered scenery.