This weekend I went to practice for a few hours with my new Sigma 150-600 "C". I learned a few things, for example that birds in flight are tricky to capture. These little rascals fly in quite irregular patterns, and hunting them with a very narrow FOV is difficult. I consider this one as the only keeper from a set of around 50 exposures. Quite a few of the others were only blue (hey, where's the bird?), many had parts of a bird in it, some had the entire bird in a weird position and some were misfocused. On this one both framing and focus is OK, but that's a hit percentage of about 2%. Gotta practice more... (I don't blame the new lens, the poor hit rate is rather the owner's fault.)
7D, 1/1600 sec, f/7.1, ISO400, Sigma 150-600@468 mm