Thanks guys. I love the Tamron 180mm and the bokeh it can produce (look at the ant pic) is stunning. I am shooting with the 1.4TC attached and a 12mm (sometimes a 20mm) tube attached so I am effectively at 250mm and roughly 1.7-1.8:1 magnification. As you can imagine, it gets incredibly hard to handhold...though more manageable with the 12mm tube than the 20mm.