The public gather on the lawn to the north and were treated to the martins swooping down over their heads from behind towards the trees. This gave an amazing sensation of motion as you can see in video.
I may have to go back after I know that my new fledglings have left to wish them well on their way to Brazil.
July 30 - A second trip to the roost this evening, to try again for interesting pictures. Perhaps we will see some of our fledglings.
July 31 - Though not an official party night, went back for a third round. Danielle took many movies. I set up the GoPro and took a long panorama movie. It is very hard to get focus on the birds high up and to get the full scope of the experience. I am having luck with setting the camera on fully manual with aperture set to f/9 or f/11 to get better DoF and setting the shutter speed lower, even as low as 250s. I can then rely on the flash to stop the action rather than the shutter since there is so little ambient light. I am still using ISO-1600 which leads to grainy picture that need much smoothing in post-processing.