When you're planning an outdoor lighting project—whether it's a parking lot, a roadway, or the exterior of a commercial facility—choosing the right fixture is only half the equation. The other half is understanding how that fixture distributes light once it's installed.
That's where lighting distribution types come in: each distribution pattern—Type II, III, IV, V—shapes how light spreads across a space. And when you're aiming for energy efficiency, uniform coverage, and minimal light pollution, getting that
distribution right matters just as much as the lumen output or mounting height.
Let's break down the most common light distribution types used in commercial and industrial applications, focusing specifically on Type III, Type IV, and Type V. These are the go-to options for most outdoor lighting layouts, and knowing when to use each can make the difference between an overly lit sidewalk and a perfectly balanced site plan.
Whether you're an electrical engineer, facility manager, or lighting designer, we'll illuminate each pattern to help you create safer, smarter spaces.
What Are Lighting Distribution Types
At a glance, LED fixtures may look similar, but the way they distribute light can be drastically different. Think of lighting distribution types as blueprints for how light spreads onto a surfaceonce it leaves the fixture.
Each distribution type is defined by the shape and reach of its light pattern. These patterns help lighting professionals illuminate their environment—minimizing wasted light, improving visibility, and staying compliant with photometric and energy codes. Whether you're lighting a narrow walkway or a sprawling parking lot, choosing the correct types of light distribution ensures the light goes where it's needed—no more, no less.
Most classifications follow the IES (Illuminating Engineering Society) standards, which break down light output into categories like Type I, II, III, IV, and V. While Types I and II are often used for narrower paths and walkways, Type III, Type IV, and Type V are more commonly specified for large-scale commercial and industrial outdoor projects.
To help visualize the differences, many lighting professionals reference a light distribution types chart, which maps the throw and shape of each beam pattern. If you're selecting fixtures for site lighting, this chart quickly becomes your best friend:
Overview of Common Lighting Distribution Types
The IES classification system breaks down lighting distribution types into several categories, each designed for specific applications and mounting conditions:
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Type I: A narrow, bidirectional beam ideal for walkways, sidewalks, or paths where the light fixture is centered between two areas needing illumination.
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Type II: A slightly wider pattern used for narrow roadways, alleys, and side streets. It pushes light a bit further outward while still maintaining a tight, linear beam.
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Type III: Being the most versatile and best choice for most applications, this distribution type is a popular choice for parking lots, driveways, and roadways, providing a forward and wide throw that covers large areas.
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Type IV: Necessary for very specific situations, this distribution provides a very narrow, forward throwing beam. This type is great for perimeters and building facades—casting light outward while minimizing backlight.
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Type V: This pattern distributes light in a circular or rounded square shape around the fixture, ideal for large lots or intersections. It’s the best choice for applications requiring an even amount of back throw.
Let's focus on the three most commonly used patterns for commercial and industrial site lighting distribution types: Type III, Type IV, and Type V. These are the workhorses behind everything from warehouse exteriors to municipal parking lots—where wide, consistent, and efficient coverage is the name of the game.
| Light Distribution Types | ||
|---|---|---|
| Type | Best For | Pattern Shape |
| Type III | Parking lots, roadways, drive lanes | Forward & Wide Arc |
| Type IV | Perimeters, building exteriors, wall-mounts | Rounded Forward Throw |
| Type V | Large central areas, plazas, intersections | Symmetrical (Square/Circle) |
Type III Lighting Distribution: Wide Coverage for Roadways and Parking Areas
If you're lighting a commercial parking lot, a long driveway, or the side of a roadway, there's a good chance you're reaching for a fixture with a Type III lighting distribution.
This distribution type casts light in a wide, forward pattern. The result is a generous spread of light that works in a multitude of applications. The broad distribution lends itself to being a go to choice for most spaces.
Type III is popularly used for:
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Parking lots
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Roadways and drive lanes
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Perimeter lighting for large campuses or retail centers
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General open areas with walkways or vehicle access
What sets it apart from the other types is the wider lateral throw—making Type III the more versatile choice for open or semi-open spaces.
Type IV Lighting Distribution: Ideal for Perimeter and Facade Illumination
Type IV lighting casts light with a further reaching and more narrow throw than the other distribution types. This minimizes light spill behind the fixture, making it perfect for areas where backlighting is either wasted or unwelcome, while providing a more concentrated forward throw for outstretching and narrow applications.
This makes Type IV the best choice for:
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Perimeter lighting along parking lots or walkways
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Building facades and exterior walls
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Perimeter roadways or lot boundaries
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Wall-mounted fixtures on commercial buildings
Its ability to direct light forward while keeping the backside relatively dark makes it especially effective in reducing light pollution—an increasing concern in urban and suburban projects.
Need a practical example? Picture a row of lights mounted along the outer edge of a commercial property. You want them to cast light into the lot, not out onto the street or neighboring buildings. That's where Type 4 distribution excels—clean, efficient, and targeted.
Revolve LED Lighting Solution: We offer area lights featuring a Type IV lens, with options for adjustable tilt, photocells, and IP65+ ratings for tough outdoor environments. It's all about giving you more control—and less waste.
Type V Lighting Distribution: Uniform, All-Around Illumination
When you're lighting a central space—think the middle of a parking lot, a traffic circle, or a public plaza—you need light that spreads in every direction with equal intensity. That's exactly what you get with Type V lighting distribution.
This distribution pattern throws light out in a full 360-degree shape in a rounded square shape. It delivers a symmetrical beam, meaning there's no distinct "forward" or "back"—just even coverage all the way around the fixture.
So, where does Type V shine the brightest?
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Large commercial parking areas
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Intersections and roundabouts
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Open lots, plazas, or courtyards
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Central poles surrounded by the area needing illumination
The real advantage of Type V is uniformity. When lighting is balanced in every direction, you eliminate dark zones and boost overall visibility. That translates to safer environments, lower energy waste, and a cleaner visual experience—exactly what facility managers and contractors aim for in high-traffic public spaces.
Revolve LED Lighting Solution: We offer a wide selection of area lights with Type V lenses. These high-performance lighting solutions are fine-tuned for trade professionals.
Choosing the Right Lighting Distribution Type for Your Project
So now that you've got a handle on Type III, Type IV, and Type V—how do you decide which one's right for your project?
It comes down to context.
Take a step back and consider the site layout, pole placement, mounting height, and what you're really trying to achieve. Is it about blanketing a wide space evenly? Throwing light outward from the edge of a lot? Or lighting a linear path like a roadway or long driveway?
Also consider local lighting codes, energy rebate opportunities, and environmental impact.
Still unsure? Revolve LED's free lighting layout service takes the guesswork out of photometric planning. Our team works with engineers, architects, and contractors daily to develop optimized layouts using the right lighting distribution for every environment.
Get the Right Light Distribution Types To Fit Your Project
At Revolve LED, we stock a wide range of commercial-grade fixtures engineered with these lighting distribution types in mind. Not sure which one fits your layout? Our team is here to help—no guesswork, just solid guidance backed by years of lighting experience. Explore our LED area lighting collection or reach out to our lighting design team for a free layout consultation. We'll help you get the right fixture with the right distribution for the right results.
