Horizons: Site-specific Perspectival Art Installation

In August 2014, my collaborator, Sebastian Martin (Instructables member HotGlue) and I made a site-specific installation at an artists' residency in Mendocino County. Lots of artists use perspectival illusions in their work, and we were inspired by the location to try one of our own. We prototyped the idea of drawing an imaginary line across a group of redwood trees with white surveyors tape. It was critical for us that the final piece be tied to that particular place and reference or enhance something in the landscape. We chose a stand of trees with a gap in the center that reveals a glimpse of the Pacific Ocean stretching out to the horizon. Our installation frames and directs the viewer's attention to this special view and virtually extends the distant horizon line out across the nearby trees.

Here's how we did it!

Step 1: Gathering Materials

We used:

• Various widths of flagging tape: 12", 6", 4", 2" and 1" widths in white purchased from Ben Meadows forestry supply.
• Scissors
• White Gaff tape
• White thumb tacks
• Small metal straightedge
• Camera and tripod
• Ladders: 5' step stool and a 25' extendable ladder
• Small gear bag for carrying materials up the ladder
• Trees!
• A stump
• Two or more people
• Time (a day or more)

Step 2: Choosing the Location and Creating a Concept Sketch

A number of factors went into choosing a good location for the installation:

• Number of trees - enough to support the illusion but not so many that we couldn't do the job in the time allowed
• Spacing - distributed across the area where the illusion was to be applied, without too much bunching or gaps so big that they'd disrupt the illusion
• Height of trees - on a downward slope the line will hit the trees in the back higher up than at the front. Our highest segments were about 30' up.
• Uninterrupted view of horizon line (the horizon isn't visible in the photo because it was a foggy day)
• Uniform "background" - the line of trees on the far side of the meadow
• Vantage point

We took a photo of the spot where we wanted to do the installation and
used Photoshop to superimpose an image of a broad white line across the trees. This gave us an idea of how thick we wanted the line to be, and whether the illusion seemed like it would be effective.

Step 3: Establishing the View Point

We gathered our materials and a thermos of hot coffee and went out to the site.

Placing the camera

We made sure the camera was level and the view in the viewfinder included the entire area of the installation. We marked the location of the tripod with a small pile of rocks and tried to leave it in place during breaks in the work. At one point we accidentally changed the position of the tripod and found it very challenging to get it back into exactly the right spot.

A note about the viewing spot

It's important to be aware that the place where you are sitting when you make this is the exact spot where your viewer will sit to see the completed illusion. We used a camp chair during the installation and later came up with a
stump that was the right height. It would no doubt have been a good idea to use the stump intended for the final piece during the installation, in order to make sure the position was right on, but this worked out ok.

Step 4: Using the Camera to Direct the Installation

One person manned the camera while the other positioned the tape. The camera person used a small metal straightedge to ensure that the lines were even in the viewfinder. Locked to a tripod the camera's viewfinder offers accuracy and precision beyond what your naked eye is capable of, and the single viewpoint eliminates parallax.

Your eye needs to be in the same place as the camera in order to really see the illusion, so it won't look right with your naked eyes unless you move the camera and put your face right over the tripod.

Step 5: Roughing in the Line

To start the installation, we took the 1" wide flagging tape and marked a thin horizontal line on all the trees in the camera's field of view. One person put up the tape, equipped with 1" flagging tape, scissors, thumb tacks and a ladder where necessary. The other person looked at the camera's screen and directed the first person to the right places on each tree.

We typically used three thumb tacks for the roughing line on each tree; they attach nicely to the redwood bark and don't hurt the trees.

The visible horizon was framed by two trees, so we began by marking those trees in the places where the horizon appeared to be touching. This proved to be critical, since the fog rolled in on the second day and stayed for the remainder of the installation. We used 1" tape to locate the top edge of the line on all of the trees that were reachable without the extendable ladder.

Step 6: Building Out the Line

Defining the line width

The thicknesses of the lines on each tree were defined by the thickness of the line on the tree furthest away from the viewpoint. We put up 12" wide tape on the tree in the background and decided that resulted in a good line width in the camera.

Adjusting the line width on each tree

Once the complete line was installed on one tree, we proceeded to adjust the line width on its neighboring trees to match the apparent width as seen in the viewfinder of the camera. Moving from tree to tree in that way, and using ladders as necessary, we installed horizontal flagging tape lines from 12" wide at 23' height (on the farthest tree) to 3" wide at 6' height (on the closest tree).

Step 7: Taking Photos and Placing the Viewing Stump

Once the camera and tripod are removed, it is very hard to reestablish the same viewpoint again. So before we replaced the tripod and our chair with the viewing stump we made last fine adjustments to create the appearance of one horizontal line moving the lower or upper edge of the tape slightly up or down where needed and securing it with additional thumb tacks.

After taking lots of photos we removed the tripod, camera and all other equipment and placed a stump such that the seated person's head was in the place of the camera. We rapped a piece of the 6" wide tape around the stump to connect it visually to the rest of the installation.

We did not put instructions as to what to do with the installation but allowed visitors to notice the markings on the trees from afar, and discover the viewing spot for themselves.