Just to echo - the 70-210 beercan works great. I use it fairly often. Last June I used it to shoot the annual air show sponsored by the Rhode Island Air National Guard at the old Quonset Point Navy base. Worked great - I was really happy with the results. In fact, I prefer the beercan on a Maxxum/Dynax 7D or 7 to my older cameras (600si and such) - there's an AF/M button near your left thumb (the sony A700 has the same)that can be set to toggle between auto and manual focus. If the lens starts to hunt around (one drawback to the 70-210), you can throw it to manual in half a second. The anti-shake lets you get away with a lot as well. I've found that I have to be careful when I shoot film on my 7 - I tend to try to use slower shutter speeds than I should.