I was trying again and again to get good shots of the swallows which constantly came back. It was a marvellous aerial display of speed and manoeuvrability. I used almost 300 exposures at rapid fire setting and after about half an hour my arm started hurting from having to lift the heavy camera the whole time. It was very bright which kept the ISO low despite using 1/4000 to 1/5000 of a second as shutter speed. I was positioned well because the swallows came flying towards me. It was a wonderful experience and certainly most difficult in bird photography due to the immense speed of the birds. I am not sure but I think there are swallows and swifts in the mix. I have to ask an expert to be sure. Enjoy.