60 feet would be plenty of distance, so hopefully CLS will work. I'm hoping I can setup within 15-20 feet of the feeder / flower display.
Thanks much for the tip on the Cinefoil.
The clearing I'm working with is pretty much a C-shape, placed in landscape mode so that the opening and background are on the longer axis. The natural backdrop will be thick brush and trees, but I can easily add a black backdrop for better contrast - another great idea.
I do have the latest 2x teleconverter, and in my initial testing it seems to produce good results with the 70-200, so I'll give that a try if I need some additional reach.