Triple exposure of tourists waking around. Red , green and blue filters were used for this triple exposure. Any moving object will take on the color of the filter used at that moment. Hence, some are red, some blue. The stationary objects like the Bridge take on the usual color. Why? Because red, green and blue filters make neutral or a gray filter. Gray filters do not change colors. I had the camera (Mimaya 645 Super, 120 film) on a sturdy tripod. I used a cable release to trip the shutter and minimize vibration from the photographer. I first determined the exposure for the film at an ISO 400 film from Kodak. I used color negative or print film. This has more wiggle room for exposure. Screw on the first filter, say red and calculate the exposure for this red filter. Simply divide the ISO by 3 and get ISO133 . Set that ISO on your cameras internal meter. Or use a spot meter and shoot throughout the filter for a reading. Your camera must be able to make a double exposure. Find out how to cock the shutter with out moving the film. On most automatic cameras this is not possible. On the Mamiya and Nikon there is a small button to disengage the film transport. You can get this effect from any scene where part of the subject is in motion. This can be used for moving water (fountains or surf), people, clouds or traffic. It's like using Photoshop in your camera but you save oodles of money by in camera manipulation.