Exotic birds of the Pantanal

My trip to the Brazilian Pantanal is coming up in a few days. I'm very much looking forward to going back, not only to photograph more of the elusive jaguars in the wild (like the banner on this page), but the birds are incredible in this tropical region of South American. One such species is this red-headed cardinal that I captured at one of the feeders of a lodge I use for my photo tour group. What is interesting about this shot is that in order for me to fill the frame with this small bird, I used a 500mm f/4 plus a 1.4x teleconverter which gave me 700mm of focal length. However, I was only about 7 or 8 feet away from the perch above the feeder and the super long telephoto wouldn't focus that close. Therefore, I had to use a small extension tube placed between the lens and the body to reduce the minimum focusing distance. Extension tubes are invaluable. They are simply spacers, with no glass, and they allow you to focus closely with any medium or long telephoto. My settings were 1/200, f/5.6, 1000 ISO, and I used a tripod with a Wimberley gimbaled ball head.