[M_Six]

Nice images. Love the compression.

My Sigma 120-300 f2.8 is also a beast. Even on a beefy tripod, and using a lens foot, it's still a bit wobbly. Trying to get something like the moon to stay in the center of the lens for fine tuning manual focus can be a pain. I have a 3-axis tripod head that helps, but that's also quite beefy. So between the lens, the tripod, the tripod head, and the 5D MkIII with the battery grip, the whole kit weighs in at slightly less than a ton. (Ok, not quite that bad, but close.)