About 4 months ago, I picked up an old Sigma 400mm F 5.6 telemacro. I am admittedly not well acclimated to this style of photography, but I wonder if this lens may fit the bill. It was available for about $500 and seems to be quite sharp at f5.6. The only nit is there is no stabilization, but then again at 1/1000 sec, I really don't need stabilization. I am curious what the experts on this forum think of this lens.