I was thinking in terms of shooting birds with 400mm with a feeder, you can forget about wild birds with the 100-400mm! Unless you spend enormous amounts of time in the blind andhave a very low keeper rate at best.Or ifthey are used tohumancontact; sea gulls, humming birds, sparows, finches ext.I wouldn't shoot less than 300mm in a set up feeder, you can do it but the pictures don't come out as nice and the better beamer (great product!) works much better at longer focal lengths. But it can be done.


I woudn't rent, it's hard to make an acurate judgement in only a short time.Unless it's for something very expensive such asthe 400mm f/2.8 L.I would do as much research as I can and buy it, lenses hold theire value very well and you can sell itin a couple months from now and not lose to much. You might figure out youwant the 70-200mm f/2.8 IS II Lor the 70-300mm L or something.


John.