Photographing Tree Swallows in flight is usually a next to impossible task. The easiest way is to wait for them to come back to their nesting box and start firing when the bird nears it hoping to capture a frame or two. This method has a very low success rate and the bird is never in the position you want. After you clone out the box the bird just doesn't look right. On the day I took this photo their flight pattern followed a dip in the grass that was wet and was attracting bugs probably from a recent hatch. The Swallows repetitively took the same route time after time and ignored me while flying very close to my head. After taking hundreds of shots I got my panning up to speed and captured some good shots. I have never seen this pattern since nor do I expect to get a head on shot of one again.