.
That super far away MFD is a concern, and I don't think there's much that you can practically do about it.
When I saw the MFD, I thought it was a lot too, but 6 meter in the field has never hindered me. You just need to have realistic expectations and use the lens according to its abilities and its shortcomings. The 800/11 is made for open terrain. It is not really a lens for the park. Edit: Just like jmckayak said as I was typing this. And in open terrain, in the fields the MFD is of no consequence whatsoever. Although you can also take it out to the park, you just have to pay more attention to the surroundings. I took it out to the park last year, to try it out and shot a magpie that was very very close. I didn't think I had enough distance, but I had. I was able to shoot the bird completely filling the frame and he was in perfect focus. But even tiny songbirds. Have a look at this, a Great tit.
A screenshot of the uncropped raw file in Lightroom:

). But I don't think I posted these particular ones before. Well, I hope not anyway. 

Plus, we can supply a few, more photogenic water birds, like Wood Ducks, pretty much year round...heh




