My fracture is far enough healed that I can support my big lens again (despite still being in a cast). Here is the last image I took with the 300mm f/4L IS + 2xTC combo. I'm frustrated in that I still don't have a good bluebird image. This one (along with 3 other pairs) I followed all over the place for about 30 minutes. Image cropped somewhat.
The electric blue back is what I'm trying to capture when they are in flight.
Time to relegate the 300mm back to macro duties