Beams of Light – Altered By Accessories

a guest post by Lisa J. Reed, Lighting Designer

Beams of Light Altered by Accessories

Lighting can come from a source in a specific direction, or it can just ooze out of the fixture in all directions. Both kinds of light have their applications, but directional beams of light can be controlled with optical accessories.

First, you must understand beamspread.

Light emerges from a directional source in the shape of a cone, and from an omni-directional source in more of a ball. When you have a cone of light, the shape of that cone is defined by the beam angle, or beamspread. A narrow, concentrated beam is considered a spot and makes a smaller, brighter pool of light. A broad, wide beam is a flood, and creates a broader pool of light. The distance from the light to the object being lighted will also affect how large the “pool” of light created by the beam will be.

Things you can control with a lens:

  1. Beamspread
    When you begin with a tight beam such as a spot, lenses can be added to create a wider beam. The spot light in both photos is the same. The only difference is a beam-spreading accessory was added for the picture on the right.
    Bare lamp, spot distribution Bare lamp, spot distribution
    Same spot lamp with spread lens Same spot lamp with spread lens
  2. Other Optical Control
    What’s cool is that we also have the ability to control other aspects of the beam of light coming from a fixture. The beam can be flattened or lengthened. The same lamp is used in all of these images. The only change is which beam-controlling lens that was applied to the front.
    Optical Control Square Optical Control Horizontal Optical Control Lengthened
  3. Color
    Lenses and accessories can also be used to modify the color or a lamp. Be aware that it is easier to go from a cool color to a warm color, though. Adding blue lenses cuts out more of the light than adding amber lenses. No matter what kind of accessories you add, the light output is reduced, so take that into consideration before you start adding lenses all willy-nilly.
  4. Glare Hexagonal-cell glare shields
    Hexagonal-cell glare shields, crossbaffles, and snoots can be added to reduce glare from the side viewing angles, but because these are typically dark in color to prevent glare, they significantly reduce light output.

If your directional lighting doesn't produce the results you originally envisioned, all is not lost. Accessories may provide just the adjustments you need.

Lisa J Reed photo - Lighting Blog

Lisa J. Reed has been attracted to lighting (like a moth to a flame) for 20+ years. She is the Founding Principal at Envision Lighting Design, LLC in St. Louis, where she designs, teaches, and writes about architectural lighting.


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