When I read reviews and comments about shows that have projected elements, I often come across the complaint that they look flat or two-dimensional. Projections are essentially light and if I am not mistaken, physics tells us that light consists of particles that flow in waves. To what degree time plays in all that seems to lead to a lot of discussion, but we already have a least three dimensions which I find sufficient. The real question is "what makes projections appear flat?" Once projected light hits a surface, it reflects back towards the viewer, material permitting. Black velvet for example is quite good at absorbing light while reflecting very little. Conversely, a flat panel of white painted wood is very good at reflecting light. The projection on the black velvet still appears to have depth, even though the image is very faint when compared to what is seen on the white, wooden flat. The choice of surface and imagery are the key to creating as much of an illusion of depth as possible.
While a projection is composed of light, it is quite particular because within the optical path of the digital projector sits at least one chip of information. That information is displayed in the form of a rasterized image with a certain resolution. For example, it could be a LCD chip with a resolution of 1024 x 768 pixels. That means there are 1024 horizontal pixels and 768 vertical pixels that can display anything still or moving. Whatever is in the chip is projected through the lens and appears on everything in front of the projector's light. The lens may not allow for the information to be focused everywhere, but the information on the chip is always constant.
The projection designer must contend with the focus of the lens as well as the resolution of the chip because these dictate the resolution of the displayed artwork. Once the information on the chip hits a reflective surface, that surface provides light with dimension. In the case of the white, wooden flat, the image will most likely appear flat because there is very little contrast to provide an illusion of depth and the surface is inherently opaque. There are a couple of common techniques to avoid flat looking projections if they are not desired.
1. It is entirely possible to project through multiple surfaces that have varying degrees of translucency and the result will be anything but two-dimensional. I frequently project on performers, into the open space and the images or textures "hit" everything in its path. This can create very interesting effects on multiple layers.
2. Judicious use of light and dark tones within the imagery can suggest depth. A projected black area can appear to have depth, but it is an illusion caused by the way the human brain processes brightness.
3. Careful choice of projection surfaces and materials enables greater contrast of the imagery and will aid in the illusion of depth.
4. Avoid ambient light spill that decreases the contrast and therefore the depth of the imagery.
5. Project on three dimensional objects. That can be anything from a sphere to a car. If done judiciously, it can create compositions with great depth.
6. Mapping projections to the three dimensional architecture of the set or stage. The whole idea here is to make the projections just as three dimensional as the architecture by aligning the projection perfectly with the chosen surfaces or facades (usually including pillars, columns, moldings, doors and windows).
The last item in the list is becoming increasingly popular. The ability to map projections precisely to the surface or to multiple surfaces in any shape or form is a very old idea. However, software that facilitates mapping techniques has become increasingly more sophisticated and affordable and thus more commonplace. It is entirely possible to project through multiple surfaces that have varying degrees of translucency and the result will be anything but two-dimensional. Projections can appear to have depth and dimension, but in order to achieve those goals, it is necessary to understand that they are light and will behave as such. Equally important is to understand the properties of any object or material that lies in front of the projected beam.