Photo Murals Make You Think Big. Really Big.
In 2004, the board of the San Luis Obispo Children’s Museum embarked on a mission to construct a new building. The grand opening last month delighted the town’s children.
In the process of building the interior spaces, I got involved as a photo-muralist. My plan was for a large interior mural for the grand staircase that rises from the ground floor to the second floor of the new museum. The idea was to make a cityscape mural that’s reminiscent of our town, but fanciful and more colorful than the real thing (Figure 1).
Figure 1. San Luis Obispo’s Fremont Theater is a beautifully restored Art Deco building. For the new San Luis Obispo Children’s Museum, I borrowed its facade for my photomural and replicated its stylish neon sign. This is a tone-mapped image. Click on the image for a larger version.
Ben and Brian’s Excellent Adventure
Ben Willmore teaches Photoshop in San Luis Obispo County a few times each year, and when he comes to town the two of us like to go out on photographic journeys. We call them “Ben and Brian’s Excellent Adventures,” and we always come back with amazing photos. We drive the back roads, and we go slowly so that we don’t miss any photographic opportunities.
Last fall when Ben and I were on one of these adventures, I noticed that for every photo I took, he shot three. He explained that he planned to combine each set of three into one High Dynamic Range (HDR) image. I came home excited to try it and to expand on the HDR concept with tone-mapping, using software called Photomatix Pro.
I Built this City in HDR
I rode my bicycle around town on a cloudy morning, taking photos of a number of our historic buildings. Cloudy days are good for this, I’ve discovered, because an overcast sky creates subtlety in the images, and that subtlety allows colors to be expanded better in the tone-mapping process. I took three bracketed exposures of each building, then used Photoshop to merge them into individual 16-bit HDR images. One way to do this is to open the three (or more) original images into Photoshop using the Merge to HDR command in Photoshop’s Automate menu (Figure 2).
Figure 2. This is the series of three exposures that make up the HDR image of the Fremont Theater. One is underexposed, one is correctly exposed, and one is overexposed. Most SLR cameras let you set them up so that when you push the shutter button, the came takes a series of bracketed exposures. The key to success is using a tripod or holding very still while the camera fires its series of images.
Once Photoshop merges the images into an HDR file, you can slide a control to define the shape of the curve of the resulting file. I’ve had the best results when changing that curve only slightly from the automatic mode, favoring the highlights a little more than Photoshop recommends. I export the resulting images from Photoshop in a format called Radiance.
I then open the Radiance files in Photomatix Pro, which is the secret ingredient for tone-mapping (Figure 3). I experiment with that application until I get the results I want, then I save the file in the TIFF format. There is no set formula in Photomatix, but once you have a successful image, you can save the adjustment settings and apply them to other images for a similar look.
Figure 3. The Photomatix Pro software extracts and enhances colors to make a wide array of results. For my images on this project, I wanted the colors to be surreal. Notice how the tone-mapping software enhances the pinks and greens of the Art Deco building.
Once I completed the images of the landmarks, I dragged them on top of a tone-mapped photo of one of a local mountain, Bishop Peak. Once the museum director and board approved the mock-up, I went into high-resolution mode to work on the final images and build the city of my dreams (Figure 4).
Figure 4. The finished cityscape is made-up of four prominent local buildings and one of our famous local peaks. I removed the Fremont Theater sign from the mural, to be replaced by a scale replica of the neon sign mounted on the same wall. Click on the image for a larger version.
Large Files and Photoshop Limits
The PSD file format has a size limit of 30,000 pixels in either direction, a limitation I exceeded while making the cityscape. Fortunately, Photoshop’s Large Document Format could handle my larger file size.
Another issue with large-format graphics like this is the dimensions of the rooms in which they’ll appear — you want them to be exact. I worked with a contractor to measure the spaces twice. These graphics cost several thousand dollars each, and making one the wrong size would be a costly mistake. Even after measuring twice, I made a mistake on one of the murals on the second floor, so it’s short a few inches on the bottom. Low cabinets installed against the same wall cover that error.
Figure 5. For this wall on the second floor, I used Illustrator to redraw a locally famous Eskimo Pie advertisement, including lifelike shiplap siding. The measurement for this mural was correct!
You also need sufficient computer speed and disk drive capacity when working on mammoth files. In March I bought the new 8-core Macintosh tower with 2 terabytes of internal storage and oodles of RAM. This system processed the massive files without difficulty, but my previous computer (an aging G5) would have had problems.
The Neon Sign in “Miniature”
The museum’s grand staircase is at the base of a 30-foot high wall. My cityscape mural would take up more than 19 feet of horizontal space, and as much vertical as I needed. I proposed that we also make a scale model of the neon Art Deco theater sign and mount it on the wall at the roofline of the mural of the theater. That, too, was approved.
I designed the neon sign replica in Adobe Illustrator and sent it off to a local sign fabricator. The sign firm used my Illustrator files to make machine-cutting instructions for their CNC aluminum cutting machine to produce some of the sign components (Figure 6). The sign maker also used the Illustrator file as a template to make the hand-bent neon tubes that form the lettering on the sign (Figure 7).
Figure 6. I drew the designs for the replica neon sign in Adobe Illustrator. The sign fabricator converted the Illustrator drawings into machine instruction files for their CAD cutting machine. Click on the image for a larger version.
Figure 7. I designed simplified letters that could easily be bent into neon tubes, and they proved to be reasonably easy for the sign maker to build.
Neon lettering is tricky stuff. I designed the basic shapes but left the exact letter-shaping to the neon expert at the sign shop. Master neon workers are pretty rare, and they earn their keep. For this sign I concerned myself only with the practicality of the letter shapes. Each tube is one piece, cleverly bent over a torch to the shape of the letter. With some opaque paint and proper mounting, the tubes turn into letters when the sign is powered up.
Over the next couple of months, I worked intermittently on the cityscape and several other photomurals on the second floor of the building. My high-resolution version was growing in size. With the four buildings, the mountain and all the related layer masks, it was approaching eight gigabytes at a resolution that was appropriate for the ink-jet printer that would print the final work.
You Can’t Do That!
That’s what the fire marshal said when she reviewed the plans to apply a flammable material (ink-jet printed vinyl) on a sheet-rock wall. We had decided that the murals should be laminated with polycarbonate plastic laminate because much of them are within reach of children walking up and down the stairs. Polycarbonate resists handprints, bubble gum, crayons, and other substances and ensures that the wall can be cleaned in the future.
The fire marshal requested fire-spread ratings for the polycarbonate before giving her approval of our plans to put these murals up. As luck would have it, we had specified the only polycarbonate made by the manufacturer that has been tested for fire-spread. The fire department approved the material in a day, and suddenly we were in a hurry to make the huge murals and get them up.
Can You Do that Really Soon?
With fire department permissions in hand, I worked feverishly to deliver the digital files to the inkjet printing firm. That company uses a solvent-based wide-format printer and outputs on adhesive-backed vinyl material, which comes in a variety of stickiness levels. We put up a sample on the museum’s wall to test its stickiness, and after three days, it failed. We tried a stickier sample that adhered so well it tore the paper off the sheetrock — now we know the mural will stay a good long time.
The printer output the 19-foot-wide mural in strips about 50 inches wide, then laminated it with the polycarbonate plastic. The museum hired professional wallpaper hanger/painter, John Cleek, to install the murals. He laid the sheets of material on the floor, aligning each pair, and then applied registration marks to the edges of each to ensure proper positioning (Figure 8). Using a felt burnisher, he carefully peeled the silicone sheet from the back of each strip of vinyl, and slowly worked his way across the mural. In a matter of hours the cityscape took shape (Figure 9).
Figure 8. Installer John Cleek assembles two of the huge strips of inkjet output for the cityscape. His register marks allowed him to position the graphic segments into a whole without any bubbles, wrinkles, or other flaws. Click on the image for a larger version.
Figure 9. John Cleek used a hydraulic cherry-picker to bring the graphics into position and adhere them to the wall of the Children’s Museum.
The Neon Sign Arrives
A few days after the mural installation, the fabricators brought in the neon sign and installed it almost 20 feet up on the mural wall. Made of aluminum, it’s quite light, but it’s an unwieldy thing that required a lot of effort to get into place. Two men with extension ladders managed to hoist it into position, route the wiring and conduit, and affix it permanently to the wall. The moment of truth was when the power was applied to the sign (Figure 10). It worked!
Figure 10. The culmination of months of work. Click on the image for a larger version. Click on the image for a larger version.
Figure 11. Another view of the neon sign in place on the mural. I had the sign maker install a long neon tube down the back of the sign to put a green glow on the wall behind it.
I’m proud of my work and happy to have been asked to make this contribution to the new museum. Every time I visit the museum, I can stand at the top of the stairs and say, “That’s my city.”