This morning, as I was working the in the backyard I heard the characteristic tweeting of small birds. I looked around and saw a very small bird hanging out in a faraway tree. Due to the distance and size of the bird I couldn't readily tell what it was. I grabbed my camera and put both the 1.4x and 2.x tele-converters on my 300mm lens. I setup my camera on the tripod, pointed it at where the bird had been and waited. After waiting for about an hour, the bird returned and I snapped a few frames. Due to the stacking of the tele-converters and wind causing the tree to sway back and forth, it was very challenging to get a decent picture. In the end I had to crank up the ISO and what you see is a 100% crop.
A quick search on wildbird.com reveals this to be an American Goldfinch, which is further confirmed when listening to the bird's voice on wildbird.
Technical Specs: Canon 1Ds2, 300mm f/2.8 IS + 1.4x + 2x TCs (840mm equiv.), f/8, 1/800s, ISO 800.