>>3178677I recommend the 300mm f/4. It's also a good general lens. Lightweight, sharp and inexpensive. Even has that funky in-built light-cover-thingy with translation I dont remember.
If you have more money, I'd say go 100-400mm. It's a better general lens althought it doesn't have f/4. The 300 is a little short for good bird photography unless you have a crop-sensor camera too. Then again, you can crop quite a bit on 5d's images so you might be alright.
