The blue emperor (Anax imperator) is a large species of hawker dragonfly averaging 78 millimetres (3.1 in) (https://en.wikipedia.org/wiki/Emperor_(dragonfly)
I spotted quite some dragonflies along the lake, but only a few of these Emperor ones.
I could clearly hear them flying away when I was walking closer because they make quite some noise. It makes me think of the sound of a small drone.
Luckily I finally found one that didn't fly away. And it was a big one too.

I started taking photos with the extension tubes between my camera body and 200 mm lens, but I wasn't even able to capture the dragonfly in total. That big was it.

I used the extension tubes to get in even closer to shoot some nice macro close-ups of it's head and body. On the next photo you can see the structure of the wings.