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April 2018

The role of photometry in a lighting layout

It is becoming more and more important to factor in the photometric spectrum when designing lighting layouts. As a matter of fact, when a light source is not controlled, it can give off visible rays in all directions, which can result in needless, often harmful illumination. The science of photometry works to contain this light by specifying the intensity and the quality of light radiation, and perfecting new techniques to control it and aim it in the appropriate areas.

In essence, when working on a residential, commercial, industrial or institutional lighting project, a photometric analysis will allow you to plan your lighting layout more accurately to control your costs and increase your energy output.

What is Photometry?

Photometry is the science of measuring visible light as perceived by the human eye. We use it mainly in the context of lighting technology whether in architectural, photographic, audiovisual, or other similar settings.

The measuring unit of illuminance is the lux, or foot-candle; it indicates the amount of illumination a given surface unit receives.

We use two devices to measure photometric data, namely the number of lumens produced by a light source:

  • The integrating sphere is used to measure all electrical features of a luminaire as well as the chromatic properties of a light source, particularly the luminous flux, or lumens
  • The goniophotometer measures the spatial and angular distribution of a light source

The 5 Basic Metric Values

  • Luminous Intensity (candela): It is the amount of light dispersed in a given direction. It is calculated in large part by guiding parts of the lighting flux such as reflectors. It is illustrated by the photometric curve.
  • Luminous flux (lumen): It is the amount of light produced by a light source. As for light efficacy, it is the result of luminous flux divided by the amount of electrical energy consumed (lumen/watts). It reflects the profitability of a light source.
  • Luminous existence (candela/ft²): It represents the spatial density of the luminous flux starting from a specific location.
  • Luminous (candela/m²): Illuminance is the sole photometric magnitude that the human eye can determine. It represents the amount of luminous intensity (candela) that an object will reflect or produce per square meter.
  • Illuminance (candela/m²): Illuminance is a measurement of the amount of luminosity that light projects onto a given surface. More specifically, it is the density of the luminous flux (lumens) on a surface. It tends to diminish as the distance between the surface and the light source increases (Inverse Square Law).

The Use of Photometry in Your Lighting Layout

Our online photometry tool will give you an estimate of the number of fixtures required in your space design. It offers a number of layout simulations of your light spots that will allow you to confirm their compliance with requisite standards and their aesthetic appearance, as well as ensure consistent light flow.

Remember, however, that it should only be used as a reference tool; it does not use the point-to-point method, nor does it determine the uniformity ratio. Rather, this software will use the mid-range lumen process, which can only give an overview of the level of illuminance.

For a more elaborate project, a full-spectrum energy audit becomes a necessity. This is where our Project Department comes into play. To make sure you reach optimal distribution of light as well as a reduction in costs, our team will suggest an array of lighting layouts. The team’s detailed report will set out the initiatives to undertake so that your lighting system offers the very best luminous efficiency, so that it ensures a substantial reduction of energy consumption, and that it affords the best return on your investment. Moreover, with this detailed report in hand, you will have easy access to the financial support available through various programs that public utility companies make available.

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Our Lighting Layout Services

A high-end fixture design coupled with a top-quality layout will ensure optimal distribution of light in any room: the perfect format to positively enhance visibility, safety and work productivity. This is why we attach an estimate to each of our lighting layout designs. What better way to optimize lighting efficiency and contribute to the energy savings of your project while reducing your costs? Our specialists are there to provide you with efficient arrangements that allow you to visualize the lighting system in a given application while ensuring the desired lighting intensity.

Learn More About Photometry

If you have any questions about a lighting layout project, do not hesitate to contact us. Our teams will gladly recommend the most desirable options to suit your needs.