There are lenses that goes from 10-410mm or with built "in" extenders 19-820mm.
That would be a sweet lens to have.
Anyway I did an experiment with the junk I have and the result is not all that bad. It not close to what "THEY" have but for a simple amature...
What "THEY" have:
What I came up with:
Nikon 70-200mm @ 200mm with extender 1.7 = 340mm