Lighted Pylons
Going back to the PVC pylon idea, I wondered if they would look good lighted with LEDs.
Short conclusion, not sure yet.
I put 5m of 12v white LEDs on a 2" diameter piece of PVC that's about 5 feet long. Wrapped as close together as possible, it made two 4" sections that are about 4" apart. That's much shorter than the 20 foot tall pylons we would need, but it is the same diameter as in the build mentioned earlier in the thread.
I also had some white electroluminescent (EL) wire that I bought a while back. I didn't measure, but it was at least 6 feet long. I wrapped it into the gap between the LED sections and a little bit below.
I didn't get home in time to try them in full daylight, but we shot them just after sundown, and then well after dark. This is in our local park at about 400 feet. (The images are cropped a little bit differently to get the file size below the max, but they are shot from the same distance.)
LEDs
My wife took the photos, and I stood near the "pylon" and plugged in the battery. Standing up to 50' away it was miserable to look at, especially after dark. In the middle of the park it looked like an alien ship was landing. But my wife said from a distance it wasn't hard to look at at all.
EL Wire
From a few feet away it was easy to look at, but from a distance you could barely tell it was there.
I thought the EL wire might be easier on the eyes at night, but it's really hard to see at all.
Red LEDs might be better, but I don't have a 5m strand of them to try.
I'm open to other suggestions (I find PVC pipe and LEDs both to be entertaining), or could drop the idea. If the schedule ends up being that we put them up one day and race a few times and then take them down, I don't think it's worth it. But if we end up leaving them up overnight, they might be a fun part of night flying.
While LEDs are advertised as low energy consumption, when I've run rough numbers in my head, each pylon would need 10-20m of LEDs, for 144-288W. Running that off batteries for several hours of evening might be impossible or prohibitively expensive.