Wild Life Lens Question.

First: There is never, EVER, enough focal length for birds.

That said, I got lots of great results with the old Sigma 50-500 EX (not OS or DG). I haven't seen a lot of folks posting with the newest, OS, version, though you could also investigate the 150-500 OS. Both have respectable MTF at 500MM. But as others said, you can get to 400 quite capably with your current kit.

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- Woody -
Equipment: Enough. For now.
Quote: 'The only thing some people will believe is their own eyes. But in the realm of the quality of a printed image, is there really anything else that can be believed? '