I've had this experience more times than i can count. Not with flying saucers, but with all manner of terrestrial things - animals, vehicles passing by, people doing things. You see it, you look at it for a bit, you think you should take a photo, and by the time you have your camera in hand and switched on, it's gone.

That’s what I’m talking about

There's a funny concept called the SEP field (Somebody else's problem) from The Hitchhiker's guide to the galaxy: https://hitchhikers.fandom.com/wiki/Somebody_Else%27s_Proble...

We could conceive of a device that would function similarly, like a "Recording device avoidance" or "improbably inconvenient timing" field.

Surely you’re joking, but I had an experience that would line up with that theory. About 6 years ago, well into the iPhone age, I saw a weird looking triangle just kind of floating in the sky. It looked to be the size of an airplane, except it didn’t appear to be using its wings to generate lift. I grabbed my phone to take a photo, but as soon as I had it pointed in the right direction, it shut off! Then it zoomed off.

A bit later I was at lunch, and my phone turned on with 40% of the charge still left.

Realistically, it was some weird drone and a failing battery. But if I allow myself to dream for a moment, that was an alien UFO.

I have wondered if the UFOs specifically exist in a plane that will always be at the edge of our awareness. They aren't so much moving through physical space, but though our collective consciousness. Similar to how a physical person may temporarily exist in your mind, a UFO may temporarily exist in the physical space, and attempting to "capture" them is like trying to control a dream.