One of the many creative things I loved to do when I first started taking pictures was making multiple exposures on one frame of film. I never knew how it would turn out and I would write down every bit of information on a notepad for each exposure, so I would know why the image looked the way it did and what I could do to make it better or do the same next roll. I have notepads still with shutter speed, aperture settings, ISO, time of day. Looking over all this, it's hard to believe that I was thinking so hard. Well, then digital and Photoshop came along and thinking as hard about the image was not as difficult. I could see the image right there and if it was exposed correct. I would use Photoshop to make one multiple image out of many images with layers. I still had to think about the backgrounds all being the same and the exposure. I also had to learn my way through Photoshop.
Most digital slr cameras don't have a multiple exposure setting. The ones that are offering it are mainly for HDR(
High dynamic range). My first digital Nikon was a D80 and it has a multiple image setting and most Nikon digital slr cameras do. The images that you see were taking with the Nikon D3. I also used a Cokin series P double exposure filter on one of the images to make it look more fused together. I still had to adjust exposure for each image so that the overall image would not be overexposed.
So, no matter what you are using film, digital, in-camera, or Photoshop, its all about trying to really think about what you are doing and create something. Learn from mistakes and try to duplicate images that you like. Below are links to taking multiple exposures in-camera. Like stated earlier if using a digital slr check the users manual to see if it has a multiple exposure setting.
lhttp://en.wikipedia.org/wiki/Double_exposure
http://www.adorama.com/CKP346.html
