What camera will you be using? One with a full frame or a crop sensor? A crop sensor will give you quite a bit more reach with whatever you choose.


I think the 500mm f/4 L IS would be perfect, but to rent that one for a week will run you about $300.


A 300mm f/2.8 L IS combined with a 1.4x Extender will run you about $235 for the same week, and do very much the same thing. Of course, you could add the 1.4x extender to the 500mm lens, but you'd have to bump up the ISO).


If you were to put either one of these on a 1.6 crop sensor, you'd have quite a bit of reach.....bird photographers will tell you they never regretted having more reach, but for a vacation, what's it worth?


Check out Bryan's "Wildlife Lens Recommendations" to help make your decision.