I have recently purchased a barely used (perfect condition) Canon 70- 200mm f/2.8L USM lens off of eBay. I am VERY happy with the purchase. It is my first good lens I've ever bought and I am very excited about it. It takes great pictures, is incredibly fast and sharp, and very well made. I live in Florida and there is unfortunately not much wildlife to shoot here except for a wide variety of birds. Now I love birds as much as the next nature photographers but my passion is filming larger animals in the west such as bear, elk, etc... Since I am in Florida 98% of the time, I would like to be able to shoot birds with my new lens. Some birds in more habituated environments (such as parks) allow me to get relatively close and they fill the frame nicely. Others however are just too small or too skeeterish for this lens length. I cannot afford to buy a big prime lens (especially after paying for this one) and am looking at getting either a 1.4x or a 2x TC to use with this lens. I hear a lot of mixed reviews about these little guys. Many say not to bother with a 2x because of the lack in sharpness. I would like to blow these pictures up real big (up to 20- 30) if possible so sharpness is a factor. However, I dont think that a 1.4x is going to be long enough. Does anyone have any experience with this combo or in this environment? I know the Canon TCs are designed for this lens. I would not consider buying a 3rd party. Also, I have a Gitzo 1349 tripod and Studioball Head so camera shake shouldnt be a problem either. Thank you so much for your responses.