Lumens: Also known as Luminous Flux, is the total amount of light produced by a light source without regard to direction. The luminous flux is provided by lamp manufacturers and common lumen values are included in the lamp matrix.
Candela: Luminous intensity, measured in candela (cd), is the amount of light produced in a specific direction. Graphically, this information is compiled into polar formatted charts that pinpoint the intensity of light at each angle away from 0° lamp axis (nadir). The numeric information is also available in tabular form.
Foot Candles: Illuminance, measured in footcandles (fc), is the measure of the quantity of light that arrives on a surface. Three factors that affect illuminance are the intensity of the luminaire in the direction of the surface, the distance from the luminaire to the surface, and the angle of incidence of the arriving light. Although illuminance cannot be detected by our eyes, it is a common criterion used in specifying designs.
Candelas/meter2: Luminance measured in candelas/meter2 (cd/m2) is the quantity of light that leaves a surface. It is what the eye perceives. Luminance will reveal more about the quality and comfort of a design than illuminance alone.
Cutoff: The cutoff angle of a light is the angle between its vertical axis and the line of sight, where the brightness of the source or its reflected image is no longer visible. This is the deciding factor which lighting designers use to determine the visual comfort in a lighting system. Deep cutoff optics provide low brightness luminaires, allowing the eye to see more effectively. The shielding angle is the complementary angle to the cutoff angle.
David Hakimi is a lighting specialist and one of the co-founders of Alcon Lighting. A graduate of the University of California Los Angeles (UCLA), David works on the front lines of the energy-efficient lighting revolution, enabling architects, designers, and lighting engineers to transition from outmoded halogen and fluorescent lighting to what David calls “the ideal replacement for all lighting applications,” —LEDs. David takes particular pride in Alcon’s design, energy, and green building knowledge, tracing his and Alcon’s commitment to quality, innovation, accountability and value back to the lessons learned from his father, a Southern California lighting salesman and consultant for more than two decades. Passionate about reducing climate change and protecting the environment, David has been particularly valuable in ensuring that his clients and customers comply with rapidly-evolving green building codes. You can connect with David on LinkedIn at https://www.linkedin.com/in/david-p-hakimi/.
Whether you’re upgrading the lighting in your current office, or designing the office space of a new development project, it’s important to consider the advantages and disadvantages of LED Lighting. Here are 4 important points of analysis when considering LED Lighting to Fluorescent.
Early in his architectural journey almost 70 years ago, now-renowned architect, educator, and urban planner Balkrishna Doshi made a quiet, powerful promise to himself in his diary, “It seems that I should take an oath and remember it for my life-time: to provide the lowest class with the proper dwelling.” And for the next six decades he lived up to his oath.
Products can demand attention with the help of proper lighting. This means an open floor plan with tactical attention to lighting fixture placement, brightness, color temperature, and CRI. The ability of LED Lighting to meet these technical requirements is what makes it the #1 choice of lighting designers and architects.
Leaf it to the horticulturalists to come up with something this big: Harnessing the power and versatility of LED lighting, urban farmers are producing 12,000 heads of lettuce per day for consumer consumption.
Tesla was a prolific inventor and patent holder. One of his primary contributions was alternating current—a development that—dare I say—powers the world we live in today. Critical for lighting. Critical for facebooking. Indispensable for all things (alternating current, not Facebook).