Today’s Question: I’ve been a reader for a long, long time. I was recently reminded about a topic you discussed a while ago, and can’t remember how to create the effect. Can you remind me how to create the “Harris Shutter” effect in Photoshop?
Tim’s Quick Answer: The Harris Shutter effect can be created by capturing three photographs of a scene that contains some degree of movement, with at least a short delay between each capture and with the camera mounted on the tripod. After capturing these photos, you combine the red channel from one image, the green channel from another image, and the blue channel from a third image to create the final effect.
More Detail: The Harris Shutter effect refers to a process that involved capturing a single image with the exposure for that single capture divided between the use of a red filter, a green filter, and a blue filter. The result was an exposure where the areas of the scene without movement appeared normal, and the areas with movement showed various color effects based on the blending of the color channels.
The same effect can be created in Photoshop by combining the red, green, and blue color channels from three separate images into a single final image.
Naturally the first step is to capture three photographs of the same scene. By using a tripod, areas of the scene that don’t have any movement will be rendered the same in each photo. Areas with movement, however, will appear differently in each photo.
You can then open all three photos in Photoshop. For each photo you can then go to the Channels panel for each of the photos and choose “Split Channels” from the panel popup menu at the top-right of the Channels panel. This will create three monochromatic channels for each image, opening each of them as individual images within Photoshop.
Next, close all but one channel for each image. For one image you’ll want to close the green and blue channels in order to leave the red channel. For another image you’ll want to keep only the green channel, and for a third image you’ll want to keep only the blue channel.
When you have only one image open for a red channel, green channel, and blue channel, you can go back to the Channels panel and choose “Merge Channels” from the panel popup menu. In the Merge Channels dialog, make sure that the Mode popup is set to “RGB Color” and that the number for Channels is set to three. Then, in the “Merge RGB Channels” dialog ensure that the appropriate channels (red, green, and blue) are selected for the applicable popups within the dialog. Click OK, and the full color image will be produced, with the Harris Shutter effect created in the process.