Light Distribution: What type is best to illuminate my outdoor area?

What type of light distribution is best to illuminate my outdoor area?

So you need to light your outdoor area? Easy right? Buy some lights, voila!

Not quite. Did you know that can have multiple types of distribution (the way the ground is lit up below the light)? And these distributions – or the shape of the light – determine where and with how much intensity the light will appear to the human eye.

Based on any given distribution type, the height that the light is mounted, and the lighting color chosen will help determine the amount of light that a ground surface receives measured in lux (or foot-candles).

By choosing the right type of distribution for your area you can avoid post-installation pitfalls that commonly happen:

The light is too bright!
The light shines in my windows at night!
There is light under the fixture but there are dark spots between the lights!
The light isn’t bright enough!
The path I’m walking on, the grass is lit up, but the path isn’t!

That’s what makes choosing the right type of light AND the right distribution so hard when you go with off-the-shelf options. Choosing the right optic type is key for making sure you get the right light, in the right place, while using the least number of light fixtures possible. And every area you need to light can be very different.

So here’s what you need to know about lighting your next project and what distribution type might be right for you.

Here’s a quick summary of the main types of distributions

Note: A photometric plot (shown below) depicts a representative distribution for a given type.

The **Type II distribution** is oval-shaped and typically throws much more light side to side than they do across the path
This type is great for lighting walkways, streets, paths and sidewalks
The light fixture is generally placed at the side of the pathway you are trying to light.

FLT Type II light distribution — The **Type II distribution** is oval-shaped and typically throws much more light side to side than they do across the path
This type is great for lighting walkways, streets, paths and sidewalks
The light fixture is generally placed at the side of the pathway you are trying to light.

**Type III** **distribution** light will project further across the path than a type II, but slightly less side to side.
This type is ideal for wide pathways, street lighting, trails.

FLT Type III light distribution — **Type III** **distribution** light will project further across the path than a type II, but slightly less side to side.
This type is ideal for wide pathways, street lighting, trails.

A **Type IV** **distribution** throws its light forward and side-to-side roughly the same amount.
Typically used for parking lots and lighting large areas, especially when you cannot place poles within the area which is to be illuminated.

FLT Type IV light distribution — A **Type IV** **distribution** throws its light forward and side-to-side roughly the same amount.
Typically used for parking lots and lighting large areas, especially when you cannot place poles within the area which is to be illuminated.

The **Type V** **distribution** projects light out in every direction and can be produced with a square or round shape (round depicted above).
Type V is the most common type of distribution used as it covers a large area – But it all depends on the shape and typography of the area you need to light.
This type of distribution is used where evenly distributed light is necessary such as large parking lots or areas where sufficient, evenly distributed light is needed.

FLT Type V light distribution — The **Type V** **distribution** projects light out in every direction and can be produced with a square or round shape (round depicted above).
Type V is the most common type of distribution used as it covers a large area – But it all depends on the shape and typography of the area you need to light.
This type of distribution is used where evenly distributed light is necessary such as large parking lots or areas where sufficient, evenly distributed light is needed.

Light distribution (and specifically what type) is important for all your projects

Lighting design, namely the type of distribution that you choose, can help you maximize the amount of light in any given area while minimizing the number of lights you need to install (hint, hint – it can save you money by needing fewer lights).

It makes sure that you are using the right type of light, in the right location, and not wasting any light illuminating unnecessary areas (like glare into a homes’ windows or the grass instead of the path on a trail).