Some would say that slide projection is dead: anything that slides did in the past, video can do better now and with more versatility. But wait! For your next event, you need to fill a surface 1000'×480' (300×160m) with an animated image. How would you achieve that in today's video world on a sensible budget? Also, video has a certain look and presentation that has entered into visual common currency. You may want to encourage your audience to look beyond the presentation and begin to appreciate the uniqueness of the building, too.

If you need to fill a very large surface with an image, there is still nothing to match a slide projector for sheer punch. They are relatively inexpensive to rent and open up a totally different palette of creative options for the designer. Obviously, we are not talking about standard 35mm slides here. Large format slide projectors have a gate size of around 6"×" (155×155mm). The more sophisticated ones are fitted with scrollers that can move the image through the gate of the projector. The top of the line machines have two layers of scrolling film in the gate and can rotate the entire gate assembly. They all have a system of controlling the film scrolling from a PC or via DMX from a lighting desk. Manufacturers include PIGI from E/T/C Audiovisuel, Pani, and Hardware for Xenon. Light output for the top of the line machines is over 90,000 lumens, and they can fill white surfaces at around 100'×100' (30×30 m).

Slide projectors can be used alone to create a show in their own right. However, in the hands of a lighting designer, they can be a powerful and versatile lighting effects generator, crossing over between image projection and animated gobos. During the 2002 Commonwealth Games in Manchester, lighting designers Andy Bridge and Andy Doig used 16×7 kW Xenon PIGI projectors, suspended from underneath the stadium canopy, projecting down onto the entire surface of the athletics field that was covered in a floor cloth to take the light. These were used in conjunction with, and as part of, the overall lighting plan.

Simply having the projectors is not the end of the story. A building is not a screen. This may seem a pretty obvious statement, but it's amazing how many times we are asked to project onto glass (through which light passes into the rooms beyond) or onto dark red brick. Neither is impossible, but both are very challenging. After all, projection screens are white, reflective surfaces for a reason. Unlike projection screens, buildings have depth and architectural detail. This can mean that an image that looks great on a flat surface can be broken up and unreadable on your chosen building. Images with lots of fine detail will tend to disappear into the architecture. The stonework of the building will absorb some of the light, depending on the type of stone and its state of repair. Sandstone, for example, has different reflective properties than concrete. All these factors will dictate the type of images that you can project. Architecture, however, also gives the designer the opportunity to use his or her imagination to reinterpret the architecture and create new perceptions of the building and use it to make the images more interesting. It's important to design for the building, not against it, and to have a feel for where you are working.

Images for building projection generally need to be bright and bold — the less reflective the surface, the more contrast is needed for the image to register as you desire. This is where scrollers will score over static images. As soon as the images move, they are easier for us to see. (My own theory is that our brain is designed to pick out movement from a background, so as to spot prey or a predator.)

The most important part of the creative process is the site survey. If you want to create and control the precision of your chosen effects, it is very important to start with accurate measurements of the building and to survey the surface. The most accurate method is to use the lens of the projector as a “camera obscura” and to draw the building through the lens. In conjunction with photography, you can then be sure that images will fit the building perfectly. Lined up slides can be created that are perfect representations of the building as the lens “sees” it. This is the way that creative magic can be achieved. With these measurements, we can produce the accurate masks that allow us to hide and reveal images within the architecture.

MASK/CONTRA MASK

Using multiple projectors, it is perfectly possible to have the image appear and disappear in front of and behind different parts of the architecture. In a “fish” effect designed by Marc Camus, the fish swims behind the pillars, while a “barber pole” effect makes the pillars of the Paris Assemblé Nationale appear to rotate. This is achieved by careful masking of different parts of the building. Two projectors are used on each zone of the building, and each projector has either a positive or negative version of this mask. As the fish scrolls behind the mask for the pillars, it appears to swim only behind the pillars of the building. The projector covering the pillars has the exact opposite mask to its pair, and so the building is covered with a moving image that plays with the architecture. This effect is called mask/contra mask.

ON FILM AND COLOR

Most designers now create images digitally. All artwork is imported into a computer and manipulated to create shapes that are, to an extent, dictated by the shape of the architecture. For scrolling images, we need to be able to create repeatable lengths of image. When we are splitting images across projectors, the accuracy of the printing of each section of the image is paramount. When programming movement, you can scroll all the projectors, and the images will line up from one projector to the next. This is possible using modern printing methods.

There are two main types of transparency film that we use regularly. Lithographic film is pure black and white image. Modern image setters can also produce excellent grayscale images. It has a thin base and allows good light transmission. This is very good for text slides and punchy portraits. This is also the main method by which we create the masks that we have discussed here. It is also possible to create a saturated color look using lith by washing the image with photo retouching inks. (The fish on the Assemblé Nationale is hand-tinted lith.)

Commercial color image setters, such as the Lambda, will output a repeatable color image at 400dpi in strips several meters in length. Being able to lay out several sheets at the same time and have them processed in the same machine means that the color and position of the image are guaranteed to be the same.

A DOME, A QUEEN, AND A UNION

One of our earliest and largest projection projects was to create a backdrop for a photo shoot at the newly built Millennium Dome in London's Docklands. The client, Imagination, had the task of making the inside — of what was, in effect, a featureless space — something that could be registered “in camera” for the launch of the Future Talk Zone — no small feat, as the space is enormous (The Dome measures 1km in circumference, approximately 3,000'). To make an impression, designer Chris Slingsby used 30 6kW Xenon projectors in a 6×5 projector grid to cover a third of the inside surface of the dome. All the angles were calculated to place the lenses flat on the surface. This meant that the central line of projectors were nearly vertical. The projectors were mounted on platforms so that they could be tipped to the required angle. A big advantage of scrolling projectors is that they do not rely on gravity to feed the slides into the gate and can — lamp permitting — run at any angle. The resulting animated image was given a feeling of scale by placing tractor trailers in the foreground.

For The Queen's Golden Jubilee in 2002, I created the projection slides for the fireworks finale with lighting designer Durham Marenghi. Buckingham Palace is an interesting surface to project onto — very good in that it is a white surface, and the architecture is quite flat in parts; not so good as we were not allowed to put any structures on the site that would obstruct the public's view. Consequently, the projectors had to be placed behind the pillars supporting the railings, positioned one above the other. This meant that none of the projectors faced center to the screen, either vertically or horizontally. To achieve good keystone correction of text slides, a thorough site survey was absolutely critical. With that done, I knew that when I designed for the surface, the relevant parts of the image would fall exactly where I wanted them. The pairs of projectors meant that we were able to cross-fade from one projector to another to change images and that we could use the mask/contra mask effect to move images through each other.

In May, Malta joined the European Union (see “Welcome Europe, LD, June 2004, p. 16). To celebrate this, a show of two parts featured lighting by Gert Hof and my projection design. The venue, Fort St. Angelo in Valletta Harbour, is a 300'×150' (100×50m) castle, and the nearest land is 1500' (500m) away. I used 150cm lenses to project images 100'×100' (50×50m). Each projector would normally be working at around 50'×50' (25×25m) under these circumstances, and so each image is, due to the inverse square, a quarter as bright as necessary. To get the intensity back to an acceptable level, we overlaid the projectors. To equal one projector at 50'×50', I used four projectors on top of each other for the left side of the image and another four for the right, all soft-edged down the middle to create one image (a total of eight projectors). This image could then be scrolled and cross-faded. In addition to this, I also decided to attempt projection onto the surface of the water. I have always felt this to be almost impossible, as the light will pass into the water and be lost. Due to the unique geography of the site, however, I could project from the castle onto the sea from a vantage point where the reflection could be viewed from the cliff top on the opposite side of the harbor. Although highly directional, the images were viewable as they scrolled out from the castle, creating various patterns of movement on the water.

So it seems that, very much alive, slide projection creates a unique look from an adaptable and versatile artistic medium, greatly enhancing and complementing lighting design and widening the possibilities of using light in a creative way.

Ross Ashton is the chief designer and managing director of E/T/C UK Ltd., a company that specializes in high power slide projection including turnkey solutions, equipment hire, and technical and design support for optimizing projection. Ashton trained in science and photography before becoming an audio-visual technician and spent four years at E/T/C in Paris before setting up E/T/C UK Ltd. In addition to large outdoor events, he creates projection images for theatre, concerts, film, and television.