double exposure effect?

I have seen studio shots (mostly fashion related) that looks like the picture has been exposed multiple times. That is, the image seems like it is composed of several shots layered on top of each other with 50% opacity. I am thinking of using bulb mode and trigger the light multiple times to get this effect. But then if the shutter is opened long enough the ambient light would kick in and ruin the image. What is the best way to do this double exposure effect?

1.) Buy some film.
2.) Photoshop.

1) Make the studio very dark
2) Place shutter in bulb mode and open up the shutter
3) Manually flash as many exposures as you like
4) Close the shutter

Enjoy! Lon

The 580EX II (among others) has a stroboscopic flash mode, allowing you to choose the frequency and duration of multiple flash bursts. Studio strobes with optical slaves could chime in, if set at low enough power levels to recycle at your chosen frequency.

A dark background will help make your subject look less transparent.

FlashZebra wrote in post #12616269
1) Make the studio very dark
2) Place shutter in bulb mode and open up the shutter
3) Manually flash as many exposures as you like
4) Close the shutter

Enjoy! Lon

^this