Slide the BoxFilter holder on the 2 bands so that it is centered on them, with the same amount of each band extending out to where they meet at the spring clamp. You should now have an upper and a lower band, free of any tangles, twists, or kinks. Bring the ends of each band back behind the BoxFilter holder, as they will be when mounted to the camera.

The small section of each band running across the rear of the BoxFilter holder should be snug but not stretched. They may tend to lie across the opening of the rear round collar. If so, move them above and below the upper and lower edges of the collar, so that they won’t get pinched between the lens and collar when mounted. Figure 1 shows the upper band properly resting on top of the rear collar.

We’ve found that it’s best to first slide the spring clamps up on the bands, judging how far based on the size of the camera. The goal is to have a bit of tension on the bands when starting to mount the BoxFilter holder. This allows the bands to help keep the BoxFilter holder in place while positioning it, instead of having to do it all with your hands.

The elastic bands can curve a bit around the camera to go alongside or around controls etc. As long as they combine to pull the BoxFilter back evenly on the lens, you should be good to go.

You should now tighten each band using the spring clamps to a firm but not excessive amount of tension. Depending on the width of the lens, whether a spacer is used, and the tension applied, the BoxFilter may try to “flip” as you tighten a band. Placing the camera and BoxFilter “face-down” onto your clean padded work surface will eliminate this if it occurs.

The correct amount of tension on the bands will vary depending on the type of camera. Cameras made of metal, plastic, or Bakelite are stronger than, for example, an old box camera made of cardboard. Use caution when mounting the BoxFilter on such cameras, or any camera which may have any sort of delicate projections, knobs, etc.

Exactly how to get the BoxTopper holder into position over the lens will depend on the camera. Box cameras are probably the easiest, since they have few if any obstructions. When a camera has a built-in strap, it’s usually on the top, so sliding the bands up from the bottom generally works best.

Once the bands are equally spaced above and below the level of the lens, place the BoxFilter holder in position on the lens, as you did earlier. You may have to reposition the short segments of the bands again so they are above and below the rear collar on the BoxFilter holder, as shown in Figure 1.

You can adjust the position of the spring clamps as needed to keep them from interfering with the red window, other camera controls, etc. For example, you may need to loosen them and pull some of the elastic band(s) through the BoxFilter slots to move the clamp(s) off to one side a bit. Figures 2 and 3 illustrate this well.

After the BoxFilter is securely in place, the ends of the elastic bands will probably be hanging loosely. To keep them out of the way, you can easily tuck them under the taut portions of the bands, and/or around other non-critical areas. See Figure 4.

NOTE: DO NOT CUT THE ELASTIC BANDS! Doing so could very likely make them too short to use on other cameras.