Understanding Light and Brightness

More Details to Consider

Understanding Light and Brightness. How to Choose the Right LED Lights for Your Space. LED lights are the future and quickly replacing older lighting technologies. They offer high efficiency, saving enormous amounts of power compared to other lighting technologies. For example, an incandescent bulb produces about 16 lumens per watt (more on lumens later), HID lights put out around 60 lumens per watt, while LED lights have been produced in the lab rated at over 300 lumens per watt.

While higher-end LEDs in regular production are around 170 lumens per watt and common LEDs in the 100-140 lumen per watt range, these are all still tremendously more efficient than these older technologies. With this increased efficiency comes big savings in the forms of energy bills and lights that typically pay for themselves, sometimes in just a few months from the energy savings. Energy savings help you keep more money in your pocket and help reduce the need for energy production, making them eco-friendly.

Whether it is the solar parking lot lights, LED stadium lights, LED corn bulbs, LED construction lights, panel lights, or high bay lights, making the switch to LEDs should be an easy decision. However, with this increase in efficiency, the old concept of picking a bulb out by the wattage just does not work anymore. It's time to start thinking about brightness and lumen output when deciding on what lights to purchase. Brightness Measures and the Meaning of Associated Terms. A few factors are associated with a bulb or fixture's brightness.

First, it is dependent on the amount of energy emitted, known as radiant flux. You are rarely going to read about this measure in lighting as it is a general term for all types of energy and has associations with radiometry. Luminous flux is the term far more specific to lighting as it is the measurement of the energy produced in the visible light spectrum. This is based on the human eye's sensitivity to light, therefore it can be considered a subjective measurement.

Some colors seem a lot brighter to eyes compared to others, so although the same energy is generated, there is a difference in brightness. The unit of measure for luminous flux is the lumen. This is the term to focus on when making a purchase of an LED light. Lumens is a measurement of the amount of light emitted per unit of time and is the statistic you will see on most lighting products these days. To keep it simple, just think of it as how bright a light is.

One lumen is the amount of light you need for illuminating a single square meter at one lux's brightness. Lux is a measurement of light covering a certain area and one of the most common units used in light plans to show the brightness of an area produced by the lights being used. Lighting professionals use the footcandle as one of the most common measure units for calculating the levels of light in outdoor and business spaces.

Concisely, the footcandle measures the intensity of light based on candelas which are also used in the calculation of lumens. The footcandle is an American lighting unit and though the equations for determining lux and footcandles are quite different, to the average person, they are simply a measurement of brightness in a given area. A good comparison would be American standard units like feet and pounds versus the Metric system with meters and grams. A simple equation that establishes the relation between lux and footcandle is that 1 fc is approximately 10 lux.

Examples of Outdoor Values of Natural Light. If there is a lot of sunlight outside, measurements of light can be in the area of 10,000 fc or 107,527 lux. On the other hand, if it is a cloudy night, then the illumination measure could be as low as .00001 fc or .0001 lux. While outdoor levels of light can top 100,000 lux in direct sun, electric lighting in a building, the level of light is commonly within the 100 to 1000 lux range (depending on the kind of activity).

For detailed and precision work and activities, the level of light may reach 1500 to 2000 lux and higher. Factors Affecting the Illumination Effectiveness. Generally, some of the factors that affect illumination effectiveness are flicker amount, glare amount, shadows, contrast, and light quality. Each element has to be differently adjusted for optimizing illumination in security situations, operations, safety, and emergency. Standards of lighting address a multitude of concerns that are associated with minimum requirements of energy, installation, placement, and design. Workplace Lighting: Tailoring Light for Task Efficiency.

From the perspective of a worker, poor lighting leads to eye-strain, stress, headaches, and accidents. On the other hand, excessive light has health and safety effects like stress and "glare" headaches. Thus workplaces have separate illumination demands that again depend on the kind of work being done. The average office space would be around 500 lux, but might be as low as 250 depending on the workplace needs. Public areas like stairwells, hallways, elevators, bathrooms, and entrance lobbies are more commonly in the 200 lux range.

Labs and places doing very detailed work, testing and visually intensive tasks may push their brightness all the way up to 10,000 lux or even up near 20,000 lux. High bay lights used in warehouse lighting are often closer to 150 lux when used more for storage, but an industrial warehouse or plant doing intensive manufacturing may be up near 750-1000 lux. Often a large warehouse may have a section for storage and stocking items needing not as much light while another section may be used for more intensive work.

In this case, more lights or more powerful lights may be used in certain areas needing brighter light. Different Lighting for Different Applications. Retail environments of all sorts tend to be on the higher side as far as brightness is concerned. Sellers want their customers to clearly see their products to help with visual appeal for sales. Supermarkets and showrooms are typically in the 500-1000 lux range. Outdoor retail environments also differ. Parking lot lights are typically in the range of 10-15 lux on the ground.

But move to an auto sales lot and that value jumps up to 150-200 lux. An area that benefits majorly from LED lights is sports lighting. Basketball court lights, tennis court lights, and other sport court lighting are all available in LED format for this reason. Sport lights have much higher lumens and high wattages. With the powerful lights used for sport lighting, the difference in energy used is huge.

One of the most common sports lights used is a 1500 watt metal halide light which is being replaced by 500 watt LED sport lights, a savings of 1000 watts per light! When you think of the fact that locations like baseball fields and other large fields can use 40, 50 and even hundreds of lights in the case of pro sport fields, you can see what a difference an LED sport light can make on an energy bill.

Secondly, LED lights use custom optics making them bright where the light is needed on the field or court and not waste any of that light out of the playing area. These optics also reduce glare, making it easier on a player's eyes to engage in sports during the night. LED sports lighting is quickly replacing metal halide and even older halogen lights on fields, courts, arenas and stadiums around the world. Horse riding, pickleball, tennis courts, basketball, baseball, soccer, football and the list goes on for LED replacements.

Professional sports have already had a large number of venues switch to LEDs. Using the high-tech optics of LED lights ensures that bright light reaches the areas where it is needed for high-definition television broadcasts. It also helps to enhance a player's visibility to make plays and fans' ability to see every play, whether it be sitting in the stands or watching from home on their TV. No matter what your lighting needs are, LED lights will get you the results you want. Energy savings helping to reduce power bills.

Brightness gains from the efficiency and precision optics of LEDs for any application. Long lasting to keep maintenance costs low. If you have trouble figuring out your specific lighting needs, make sure you call and get help from an expert!