Dawg,
Since you do nature work, you will like your 70-200 on both of your bodies. The f/2.8 "L" version is one of my main lenses, especially on my 5D. However, if you include wildlife photography, you will eventually want to consider two additions: a 400mm (either a telephoto such as the 100-400 "L" lens or a fixed 400) and, especially more short -term with your 70-200, one or two teleconverters. I have the Canon 1.4x and 2x TCs and occasionally I do use them for more reach, even with my 100-400 lens (using manual focus).
Tony
Tony Long Photos on PBase
Thanks guys. This info really helps me relax wit with my decision. Tony I had the 100-400 and sold it, but did recently get a Canon 1.4 extender for my 70-200, but what I would really like would be the 300 2.8 which is about as far outside my reach as the MarkIII.


