Thanks
Dragonflies like Hawkers and Emperors usually patrol a patch so just watch for their movements, then try to pick a bit of pond/river with a decent background. I shoot in manual 1/1250 will slow the wings down plenty so start there, f8 will give you a reasonable DOF but try to keep your ISO within the limits of the noise your camera puts out. Manual focus as well. Focus on a bit of bank about the distance the dragon has been flying, 300mm is a good starting point as anything over gets more difficult to track 600mm is very hard and I then keep both eyes open. Dragonflies are very contrasty so easy to tell when in focus. I have shown a few people how to do it after they thought it was impossible and they got results after a short time trying. It is addictive though.