Frames

The frame is perhaps the most common architectural optic device. It is an opening or a window of any size, proportion, position, or shape. The frame affects light effect by way of its edges and position with respect to the source of light and receiving surface. While a frame may be completely open, it does often hold a window that acts as a thermal barrier and weather barrier. It is important that the transparent surface, glass or otherwise, is as planar as possible, such that the trajectory of the light that passes through it is affected only by the uniform refraction that occurs as light enters and exits the medium.

Frames can exist as a single opening or as an array of openings and can exist in a number of orientations, producing a great variety of light effects. When the frame occupies an entire, exterior-facing wall of a room, it produces a neutral image. The interaction of surface edge and light produces the simple image, and textural light and a secondary source can also be produced when light and surface are brought into proximity to one another in the adjacent and opposite orientations respectively. Due to the reflectivity of the transparent medium, light that is not transmitted produces a visible but faint specular image on the medium’s surface.

Sample Series of parameters applied in sequence to the base optic device

Lenses

The primary characteristics of the lens are its transparency or reflectivity and the curvature of its surfaces. Two of these characteristics in combination produce a focusing and deflection of light from alternate areas of the receiving surface. This optic device is rarely found in architectural work and instead commonly exists in the form of glass tumblers, reflective welded surfaces, adjacent bodies of water, and imperfect planar surfaces. The inclusion of this device as an architectural device can produce significant effects that are unique in their form and notable for their relative rareness. However, because the effect relies on fluid patterns of refraction due to the curvature of one or both surfaces, the incident light must be directional and intense for effect to be produced.

Apart from this incidental parameter, the lens can manifest itself in a variety of forms, both large and small, with single or dual curvature, and with first and second surfaces that are uniformly or non-uniformly curved. Unlike the frame, the lens is harder to integrate into an architectural assembly and has therefore been proposed in its neutral state as an object that sits within the room. This device requires physical experimentation in order to produce precise caustic light, but can be introduced as a less precise interpreter of light information within a space as well.

Sample Series of parameters applied in sequence to the base optic device

Screens

The screen is another fairly common architectural device. In the case of a curtain wall system that involves structural framing or structural silicone, a screen is an intrinsic part of the system. Screens often exist within the frame (another optic device) as decorative or sun shading elements. However, the screen can stand alone in warmer climates or within or outside a thermally broken element such as a window. Screens are significantly present in historical architectural work in the form of such elements as the mashrabiya, a traditional element of Arab architecture, as well as in contemporary architecture in the form of both environmentally- and mechanically-driven kinetic screen systems.

The possible variety of the architectural screens is well-established, with such parameters as its materials, unit configuration, array type, and orientation guiding and diversifying their design. The screen as an optic device, however, aims to address the qualities of light that are produced by the screen within the space whose light reception it modulates. Though screens can be designed to control the amount of light that enters a space in the interest of reducing solar gain, parameters such as the screen's thickness and proximity to the opening/light source and any secondary light sources play a significant role in shaping the simple image that is formed by the interaction of light with the edges or material of the screen.

Sample Series of parameters applied in sequence to the base optic device

Diffusers

Diffusers are primarily used in architectural work to reduce the directionality or intensity of incident light. When light-sensitive materials are present in a space, a diffusing mechanism can be used to provide ambient illumination and indirect access to daylight while significantly reducing the possible degradation of the artifacts. These optic devices can also be used to preserve privacy or improve the distribution of light within a space. The parameters that inform the nature of the diffuser can include its size, proportion, translucency, reflectivity, geometry, and the possible introduction of a covering panel. Where a covering panel is not used to obscure the source, thickening the frame of the opening produces surfaces of a more significant surface area around the source that can act to diffuse the incident light.

Because this mechanism relies on diffuse reflection, it will most often produce the archetypical effect of a secondary source, wherein light that directly enters the space is reflected onto another surface which then also acts as a source of light within the room. Diffusers can also exist at a much smaller scale within an architectural space. Mists and clouds are diffusers because the size of the water droplets is similar to the size of the wavelengths of incident light that interact with them. Mie scattering, a process that equally scatters all wavelengths of light in all directions including the forward direction occurs, and the scattered white light appears diffuse while each droplet appears as a miniscule secondary source of light.

Sample Series of parameters applied in sequence to the base optic device

Mirrors

Plane mirrors are commonly found in homes as artifacts of daily living and in larger spaces as the finish quality of certain materials such as glass and metal. Plane mirrors produce a specular image of light that is arriving from another mirror surface or from objects and scenes that exist at another location. It is the preservation of the image and the almost complete reflection of the incident light, a result of the surface being optically smooth, that allows the mirror device to carry light further into a space or to an unexpected plane or surface. Parameters that inform the mirror device include the curvature (specular image distortion), faceting, (specular image fragmentation), number and adjacency of mirror devices, and the smoothness of the surface.

Though it does not concentrate light, light that reflects from the surface can be observed to produce a bright white or golden image of the mirror surface on nearby surfaces that are not optically smooth. The brightness of this image, that can often appear on shadowed surfaces, gives it the appearance of a caustic image, though it is not technically so. The smoothness of the surface can also affect the quality of the specular image that is produced, which may or may not be desirable to the architect. The surface of a reflecting pool may also act as a mirror device, as shown.

Sample Series of parameters applied in sequence to the base optic device

The Receiving Surface

In some cases, in order to for the viewer to fully perceive an effect of light, a receiving surface must be present to register the operation that has been performed by the primary optic device. For two out of the five primary optic devices, namely mirrors and diffusers, it is often the case that the role of the receiving surface, a secondary optic device, is performed by the primary device. A water droplet that scatters light is also the material from which the effect’s light arrives to the viewer’s eyes. This secondary device is therefore not an essential component of every light effect, but it does have the capacity to transform the light arriving to it from a primary optic device through the adjustment of its own parameters. The receiving surface is not always solid, does not always have a certain order of texture, is not always uniform in colour, and is not always planar. All of these parameters affect how the surface registers light, and this in turn affects the patterns of light that we observe from the receiving surface and the sensations that they evoke.

The receiving surface plays a critical role in the formation of the specular image, secondary source, and textural light archetypes, as these archetypes of effect are produced as a result of the receiving surface’s parameter of roughness. At an extreme, the receiving surface can become a primary optic device (the mirror). Though primary optic devices can be deployed in combination, it is perhaps more common in architectural practice to observe a layering of receiving surfaces such as stone and glass. These compound interactions can be difficult to simulate and study, but can significantly influence the registration and subsequent perception of the light effect. The loose parameter of layering is therefore particularly applicable to this secondary optic device, and it must be given its due attention in the course of the design of light-driven tectonics.

Sample Series of parameters applied in sequence to the base optic device