Hi everybody, I'm Franc Anderson, and I'd like to tell you how to make a double exposure on a camera that uses film. A double exposure is where two photographs are put onto the same frame of film. First of all, the first photograph is made as normal, then the the shutter is worn down without advancing the film and a second exposure is made, putting the second picture superimposed upon the first. This requires a lot of experimentation, trial and error, but as a guide think very carefully about the pictures before you begin and try to imagine the final result. So that for example, if you want to put a cat into a glass you photograph the glass and then you photograph the cat. The trick is to reposition the cat so it looks like it was in the glass. This is not so easy with a live animal. It's a lot easier with still life subjects. But it's fun to try, and it really is worthwhile when you get a good result. With a film camera, normally after you take a photograph and you wind on this action cocks the shutter and also advances the film inside. When you want to make a double exposure you want to cock the shutter, but you don't want to move the film so that the second picture is put on top of the first. I can show you how to do this very simply. Let's open the camera up. There is no film in this camera, so let's open the camera up. Normally, the film is stretched across the back of the camera, and the film is driven by these sprockets here, so that when I cock the shutter the sprockets advance the film. I can stop the film advance happening by simply holding in the film rewind button. This disconnects the sprockets from the wind on, and so now I watch when I cock the shutter this sprocket doesn't move and the film stays still. So, now I when I press the shutter again the second picture is made on top of the first. It's really that simple. All you have to do is make the first picture, hold the button at the bottom, and cock the shutter. The film hasn't moved, and when I make the second picture it will be on top of the first, easy. All manual cameras have a button on the bottom for rewind. All you have to do is remember to hold it in. Of course, this is made a lot simpler if the cameras are on a tripod. Then the frame doesn't move, and you know exactly where the original picture was taken. This doesn't apply to digital cameras, because with digital cameras the same superimposition of two frames can be done in software, and there's no need to have a facility on a digital camera to be able to do this. It doesn't use film.
