1) on the Sony RX100 III - the Digidapter™camera screw crashed into the platform positioning screw on the right side of the camera (2) and prevented me from tightening the camera down. I resolved this by reversing the platform screw (large screw on top and small hex screw on bottom). To keep the camera position square I positioned the left platform screw (3) behind the camera so that tightening the camera down to the platform wouldn't rotate the camera. Now I can loosen the tripod screw, remove the camera to replace battery/card, and reposition it back on the Digidapter™ for perfect realignment. The modifications worked perfectly, as I would soon find out.
Kenn Kaufman (2011) has a wonderful writeup on the differences between the medium-sized terns (Common, Forster's, Arctic, and Roseate) that is worth reading. He describes in great detail all of the nuances and differences between these birds, including age, molt, wing projection, underwing, upper wing and tail patterns, and more. Its much easier reading than the more technical Pyle Guide, and helped me confirmed what I saw through the scope.
Compare with the 'dark wedges' seen with Common Terns in flight.
Now compare w/ Forster's Terns in flight. Only the wing tips show some darkening, while the chest and belly are almost completely white (in contrast to the dark gray chest/belly of the Arctic Tern).
Just before reaching the car I spotted a Pied-billed Grebe that was sitting on the far dike. I couldn't leave without grabbing one last digiscoped image for the night.
Pyle, P., Identification Guide to North American Birds, Part II, 2008, Slate Creek Press, CA.
Kaufman, K., Field Guide to Advanced Birding, 2011, Houghton Mifflin Harcourt, NY.