Home Lighting

Objects lighted by a point source. © Jay Graham Photographer and made available from Acuity Brands Lighting, Inc.

To get the right effect from your lighting, it pays to know how different sizes and shapes of light sources affect how people, objects and surfaces will appear when illuminated. An important step is to know whether the light source you want to use is a point source, linear source or area source, which provide a palette of choices ranging from a high level of intensity and shadowing for point sources to very little intensity and shadowing for area sources.

Point sources are small lamps (light bulbs), often using a clear outer glass bulb that reveals the arc tube or bare incandescent filament. Incandescent, halogen and LED lamps are typically point sources. The light produced by point sources is generally intense, and more likely to produce pronounced shadows. As a result, point sources are ideally suited to accent lighting—individually highlighting art and other focal points in a space—and any application where we want to accentuate detail through shadow, such as grazing a brick wall to visually enrich its texture.

Linear sources emit diffuse output from the surface of the lamp, softening shadows. Tubular and compact fluorescent lamps are examples of linear sources. These lamps can be very effective for ambient lighting in work areas, cove lighting and wall washing for large surfaces.

Area sources are not electric lamps but instead large non-specular surfaces that reflect or emit diffused light output, such as a ceiling reflecting light from an indirect luminaire (light fixture), or the surface of a luminous bowl pendant luminaire. When washing a light-color wall with light, for example, the wall itself will become a light source in the space, reflecting light from the wall to other parts of the space.

All photos: © Jay Graham Photographer and made available from Acuity Brands Lighting, Inc.

What You Need To Know About Choosing The Right Lighting Source

• How light is emitted from a source determines how objects appear
• Point sources are intense sources that emit light from a point and accentuate shadows
• Linear sources are soft sources that emit light from the lamp surface and soften shadows
• Area sources are room surfaces reflecting light, resulting in very soft distribution