Sorry about another ghost shot I've become a bit obsessed with generating these ghost like images under different conditions. This one was actually taken when it was quite dark.
A bit boring unless you are into the search for ghosts. Best seen on the black background, I think.
It gives you the basic idea of how to get the effect. Then it becomes a matter of playing with the settings and timing to get the exact effect you want. Basically you use a long shutter speed and only stay in the frame for part of that exposure time. The less time you stay in the frame, before ducking out, the more transparent the ghost will be. As I discovered, wearing lighter coloured clothing will reflect more light and make the ghost (or that part of ghost) appear more solid than wearing darker coloured clothing.
It gives you the basic idea of how to get the effect. Then it becomes a matter of playing with the settings and timing to get the exact effect you want. Basically you use a long shutter speed and only stay in the frame for part of that exposure time. The less time you stay in the frame, before ducking out, the more transparent the ghost will be. As I discovered, wearing lighter coloured clothing will reflect more light and make the ghost (or that part of ghost) appear more solid than wearing darker coloured clothing.