I have finally gotten my dream lens. The season for birds is just starting here in north Florida. Weather permitting I'll get a chance to go out Sunday the first time with my new lens. My Canon 600 mm IS arrived yesterday I also purchased a new tripod (gitzo 1349 cf and a Wimberley head) to help support it nearly 12 lbs weight. It's the pinnacle for the L series lens and renowned for it's sharpness and speed. I can't wait to get out and use it.