Quote Originally Posted by AllanMarcus View Post
I have a Sigma 70-200 f2.8 monster, and an equally sized 135-400. In both cases the lens comes with a mount bracket to mount on a tripod. I use a bogen quick release and a bogen ball head and I have no problems since the center of gravity is "in the right place" when you use the included mounting bracket.

-Allan
Thanks for the reply Allan. How does the alpha like these lenses?