Chromatropes - Artificial Fireworks

We've put a chromatrope on the first page of this unit, but thought you might like to see some more.

The two chromatropes in this column use two contra-rotating pieces of glass, driven by rackwork and a handle operated by the lanternist - thus they can be shown moving in either direction. For the purposes of these web pages, we're generally showing them at 10 frames a second - if we made the gifs (the moving format we use) larger, we could make them smoother, but they would take longer to download, so we choose an optimum display rate. When shown from a lantern, they are smooth, with the speed depending entirely on how energetic the lanternist is feeling!

Sometimes we're told they look like kaleidoscopes, but that's not quite correct. Magic lantern shows could contain kaleidoscopic images, but there's a special lens for the lantern to create that effect.

Some slides are a combination of rackwork providing rotation, with stationary or sliding glasses.

For this slide, the chromatrope is created around the edge of the image, with the circular patterned glasses also carrying the fish. A stationary slide holds the fish bowl and curtains.

Adaptations have been made to both the slides in this column to create these computer animations. When projected from a lantern, blackouts hide aspects of the images; sometimes for the computer, the process has to be 'reversed', a transparent area created for an image to shine through. The fish in the slide above are against black for projection; to create the image you see here they are used on a transparent background.

As above, the chromatrope uses two contra-rotating glasses for the effect around the edge but this time a single still glass in the centre.