An amazing image.
It’s the nothing!!!
It is pretty nice, isn’t it?
He’s got dozens of them at his website, if you just click on his name in the APOD credit. He doesn’t go into the technical details, but he does give a personal history of his telescopic exploits on his “about” page, which at least names the telescopes and camera types. Of course, it’s the technology that makes this possible, but it takes a lot of skill and dedication to use it to full advantage.