The other day, after feeding the bird, I started sneaking up on this red squirrel cleaning up underneath one of our feeders. I kept moving closer to him until I could have reached out and touched him (or so I imagine). He looked like he was always keeping one eye on me.
I shot this with the 50mm prime lens at about f/2.0. It's fascinating to spend time with this lens: unable to zoom without walking or crawling, stuck with the same field of view, oblivious to shutter speed because you can get to f1.4 and getting wicked sharpness right out of the camera.
I'm also falling further and further in love with square cropping for so many photos these days.