Janette and I were shown a picture of a supposed 'spectral trail,' reddish in color. They claimed it had to be paranormal, as the 'trail' was going behind a person's head. Unfortunately, we don't have the picture to show you, but we can show you how we recreated the effect.
When I saw the 'trail' picture, my impression was that of something in front of the camera lens, blurred to the point of looking semi-transparent. (Stuff out of focus in front of the camera will have a semi-transparent look to it.) Janette pointed out that the area where it was going 'behind' was white and that darker areas nearby had a pink tint to them. This lead me to suspect a string of some kind - perhaps an unravelling sweater?
We decided to put that theory to the test.
Since this 'ghost' photo, like most of its kind, looked like the photographer's experience in photography wasn't far beyond that of the casual family photographer, we did our best to make our photos look rather blurry, focusing the camera on somewhere farther away than where we shot.
To recreate the red 'trail,' I took a piece of thread and twisted it over twice. This made it thick enough that it was fairly easy to hold in front of the camera. We had a setup we were playing with that had a white string weighed down by a small bottle - an impropeteau plumbob. For the following photo, Janette held up a piece of white fabric.
At first glance, it looks like the red 'trail' is behind the string and fabric. But look close - you can see that it's managed to give the white areas a tint.
Other photos we saw featured white 'trails' with shadows behind them. We haven't yet managed to imitate them to a point which we feel is satisfactory, but we've come up with a few that are close.
The first photo is of a phonecord. The second two are pictures of the strap from Janette's camera bag. The strap itself is black, but it's reflective enough that a flash can make it look gray or even white if close enough.
Personally, this bad boy is my favorite - trails AND orbs!
It's the phone cord held to cross over itself. The orbs were likely caused by stray bits of lint sticking to it.