1/400s f/6.7 at 500.0mm iso400

Wide open again, 100% Crop, raw image shot Standard Pic Control; sharpening replaced with USM 83/5/0, saved as JPG Quality 84

Selected from a handful of similar images, shot on a G1410 tripod.

I can add another 100 images but nothing changes; this lens, TC and camera should be shot wide open :-)