How to make and use a Harris Shutter

PSA Journal, June, 1995 by Fran Van Wagner

The purpose of a Harris Shutter is to add three separated colors to any moving object within a photo, while rendering all stationary items in their natural colors.

This heavy-cardboard attachment is described in Kodak's "7th Here's How" by Mr. Harris, but no dimensions are given. I will give exact dimensions of my own version with precise instructions for cutting the basic pieces out of two 16 x 20 inch pieces of one-eighth inch cardboard or mounting board. An optional facing for the slider can be cut from any lightweight cardboard.

Your local framing shop can do the cutting at a small price, including the square and round holes which are best done on their machines. They can also supply the cardboard, sometimes from scrap. Be sure to give them a copy of the diagrams.

If you cut the pieces yourself, use a sharp utility knife, a sturdy metal straightedge and a cutting surface that will not damage the knife.

You will also need a roll of black #235 photographer's tape, some silver #805 slide-masking tape, a retaining ring and an adapter ring to fit your largest lens, about 3 feet of twine, and three 3-inch square Wratten gel filters (one Red #25, one Green #61, and one Blue #38A, which are about $6 each).

To assemble, glue the retaining ring in the round hole of the back panel so that the screw threads protrude out the rear. This should be a snug fit, flush on the inside of the box.

Lay out the back panel, threads side down. Lay a stack of three side rails along the inside of the perimeter on each side and a stack of three bottom flats along the inside of the bottom edge between the side rails. Do not stand these rails on edge: lay them flat. Test the fit by inserting the slider between the rails to make sure it will slide in and out easily. Glue or black-tape the three rails to each other on each side, then do the same with the bottom flats. Retest the fit before taping or gluing them to the inside of the back panel.

Match the sides of the lens hood to form a flaring shape. Then tape these four joints inside and out, then tape the smaller end to the outside of the square hole in the front panel.

Lay the front panel upon the side rails, with the two openings opposite each other, and tape the sides and bottom. You should now have a thin rectangular box open at the end nearest the two holes.

Handling the three gels carefully, lay them out over the opening in the slider, with red at the top and green at the bottom. The gels should overlap the edges of the slider by about one-eighth inch. Use the silver tape between the gels, then apply black tape around the edges of the gels to secure the gels to the slider, keeping the tape smooth and flat.

Slip the slotted cap over the slider tab, tape it top and bottom securely, and test it to make sure it will close the box completely when the slider is fully inserted. If the slider fails without hindrance within the box, finish the top of the slide rails with black tape.

Tie one end of the twine through the hole in the pull-tab; then with the other end, tie a loop around the neck of the lens hood, so that when the tab is released from the notch, it won't be lost.

This version of the Harris Shutter will last for years, but the gels must be protected from scratches.

To use the Harris Shutter, attach the front of the lens to the box by means of the adapter ring. If you are using a smaller-diameter lens, place step-down rings between the lens and the adapter ring. A telephoto lens is most useful because it extends the box away from the tripod legs and also because it magnifies the effect of motion.

Before inserting the slider, frame and compose the scene, then take a meter reading, preferably with a gray card, using your TTL meter. Read the meter at one-thirtieth of a second, then change your setting on the camera to "Bulb." A polarizer between the lens and Harris Shutter will help to saturate the colors and the effect is strongest in sunlight.

Insert the slider part of the way and hold it in place by inserting the pull-tab in the notch, so that slider and gels are extended above the box, and the lens is blocked by solid cardboard.

Using a locking cable release, lock the lens open and make sure the box is hanging absolutely vertically.

To make an exposure, pull out the tab carefully, allowing the slider to fall. Be careful not to jostle the camera as you release the slider. Unlock the cable release and advance the film to a new frame.

You may wish to bracket these shots, as not ail sliders fall at exactly one-thirtieth of a second. You can ask your camera repairman to time your Harris Shutter on his machine. He should make two or three tries, in order to be sure he's testing it while the box is absolutely vertical. Write that shutter speed on your Harris Shutter. While this device is less useful in a high wind, you can achieve spectacular results with surf or falling water, children at play, white birds taking off, etc. For exposures below your smallest aperture, use a neutral density filter. You could add a star filter or other special effects filters to your lens. As you add filters, keep an eye on your polarizer to see that it has not turned too far, because at "Fully Polarized," it can cut two stops of exposure from your image.