These images are presented in chronological order (the date they were taken) and represent two of the three different techniques I have tried to date:
- Superimposition; and
- Ambient light (with or without movement).
- (The third technique involves the use of a flash gun".)
The photo below is a bit of an orphan as it was my one and only attempt at using superimpostion as a means of capturing a partial exposure.
This was taken with my old Voigtlander. Newer cameras (including my Nikon F80s) would make this considerably easier as it's possible to exposure a single frame more than once without touching the camera body (so long as you have a cable release). That said, I haven't tried it and the user's manual tries to dampen your hopes for success.
One thing I have not attempted is to take a shot of the main subject (the person) on a black background and a shot of a location in which to place them (but my immediate though on this is "Why bother?".
Ambient Lighting (with or without movement)
I gave up on the idea of superimposition very quickly and started to experiment with partial exposure of the subject in order to achieve the effect of a tranparent human being (a ghostly apparition).
I had a lot of fun doing some of these (as well as those taken with a flashgun).
The technique (in its simplest form - a subject in a moderately well lit room) is really very simple. Work out the correct exposure for the background, mount the camera on a tripod, seat your subject in the frame, open the lens and, part way through the exposure, get them to change location or quickly exit the frame.
I regret that I did not follow the golden rule when taking many of these photos - I did not make a note of the aperture or the shutter speed. It was my habit to take most bulb photos at f16 (the limit of my old Voigtlander). More often than not, it was dark and I was not usually in a fit state to be worrying about formalities such as note taking!