After the first couple of sessions chasing dragonflies, the technique had developed enough to capture them, but what was needed now was better focus across the whole subject. The first port of call was focus stacking where a series of photos are taken moving the focal plane through the subject (like a hospital CT scanner) in a series of shots with different areas in focus. Using software, it is possible to focus-blend the photos together to create a subject that is sharp in focus all the way through. One of the reasons for buying the Canon 5D Mk4 was that it had very good autofocus, but having the camera on a tripod made focusing accurately on such a small object difficult. However, the Mk4 has a digital screen on the back of the camera showing the sensor live. By zooming in on the screen, it is very easy to achieve the exact focus needed. Hurrah! There is one small flaw, each shot requires to go through the multi-step process to focus as the Mk4 resets the settings back to the beginning after the shot is taken. Clearly, with live subjects that is not going to work. An alternative is to increase the ISO, which makes it possible to set the aperture to between f8-f11 giving a deep enough depth of focus.
The next challenge was to get more dynamic photos. Catching them in the air needed another strategy. There was no hope, with how quickly they move, to capture them flying by hand. Even with the tripod set up, it quickly became apparent that catching them taking off requires anticipation beyond human reflexes. Instead the best chance was to capture them as they were coming into land. To get the focus became even more of a challenge because the plane the dragonflies are moving in usually only intersects with plane of focus at an angle so some good fortune is required that they move through the in-focus space, and to capture that moment at the same time. To improve the odds the aperture settings were f8 and then f11 to increase the depth of focus. The other tips are switch to burst mode (the Mk4 achieves 7 frames per sec) when taking the shots and use a handheld trigger so it is possible to watch the scene to anticipate the dragonfly's return to its perch. Of course, obviously using a trigger will reduce unwanted camera movement.