LEDs 101: Quality

LED lighting has become increasingly popular in recent years, and for good reason. LED lights offer many advantages over traditional lighting options, such as improved energy efficiency, longer lifespan, and better colour accuracy. However, with so many different types of LED lights available on the market, it can be challenging to know which ones are right for your needs. In this ultimate guide to LED’s, we will explore everything you need to know about LED lighting, from colour science to quality considerations.

Colour temperature, CRI, and colour consistency are all essential factors to consider when choosing LED lights for your home or business.

Colour Temperature

Colour temperature is a measurement of the hue of light emitted by a light source. It is measured in Kelvin (K) and is typically described as warm, neutral, or cool. Warm light has a colour temperature of around 2700K to 3000K and is often described as yellow or orange in colour. Neutral light has a colour temperature of around 4000K to 4500K and is often described as white. Cool light has a colour temperature of around 5000K to 6500K and is often described as blue or white.

When selecting LED lights, it’s essential to choose the right colour temperature for your needs. For example, warm light is often used in living spaces such as bedrooms and living rooms as it provides a cosy and inviting atmosphere. In contrast, cool light is typically used in areas that require a lot of focus, such as offices and workspaces, as it provides a bright and energising environment.

Colour Rendering Index

The Colour Rendering Index (CRI) measures the ability of a light source to accurately show the coluors of an object it illuminates. This is done on a scale of 0-100, with 100 being the highest score possible. We use CRI to benchmark artificial lights against natural sunlight, which achieves a perfect score of 100.

For instance, when looking at a lemon under natural daylight, you would see a vibrant yellow because all colours of the light spectrum are being absorbed except for yellow, which the lemon reflects back. But if you look at the same lemon under a poor quality artificial LED light, it might lack that vibrant yellow colour because the light itself is deficient in yellow.

Without delving into the technical aspects of how the score is calculated, what we are interested in is this difference. Sometimes, the reproduced colour may appear quite similar, while other times it may appear vastly different. It is this similarity that CRI measures.

So, what should you look for when purchasing LED lights? Our recommendation is to choose LED lights with a CRI of 92 or higher, almost always.

While we will delve into lumens below, it is frequently noticed that there is a relationship between CRI and lumens, but it can be easily misunderstood. Lumens are the metric used to describe the brightness of a light source. CRI, on the other hand, is a metric that rewards delivering colours across the entire spectrum, while lumens will increase when you focus on a narrow spectrum of light. This is why high CRI LED lights will typically produce fewer lumens than lower-CRI/standard cool-white lights.

In the pursuit of energy efficiency, you will lose colour quality – period. This is why it is crucial to choose the appropriate lighting for certain applications. For instance, outdoor lights may not require such a high CRI because the objective is simply to light up a space, whereas indoor lighting should focus more strongly on CRI to ensure colours are accurately displayed.

Colour Consistency

Achieving consistent colour quality in lighting is crucial for ensuring that the intended ambiance and aesthetic are achieved. Colour consistency refers to the degree of variation in colour quality among a group of identical lighting products. Although one would expect identical lighting products to produce the same light, the degree of colour consistency can vary based on factors such as the product, manufacturing process, and standards followed by the manufacturer.

To measure colour consistency, the industry uses a metric known as Standard Deviation Colour Matching (SDCM), also known as the MacAdam Ellipse. The rating ranges from 1 to 8, with 1 being the closest match and 8 being the furthest. A rating of 3 or less is considered very good and suitable for most applications, while a rating of 4 or higher is considered less consistent and may not be appropriate for applications where colour consistency is crucial, such as in art galleries or museums.

When choosing lighting, it is important to consider the SDCM rating in addition to other factors like energy efficiency and cost. Poor SDCM ratings may result in more energy-efficient and cost-effective lighting options, but they may not provide the necessary colour consistency for the project. Retail lighting, for instance, is an area where colour consistency is essential to ensure that products are presented in the most appealing way possible. Therefore, it is recommended to choose lighting fixtures with an SDCM rating of 3 or less for retail lighting.

Our Faze down lights have an outstanding SDCM rating of 1.5, making them one of the best-rated options in the lighting industry. For exceptional colour consistency, the Faze Pro or the Edge 100 are excellent choices.

Lumens and efficacy are two critical factors to consider when choosing LED lights.

Lumens

As mentioned above, Lumens are a measure of the total amount of visible light emitted by a light source. The higher the lumens, the brighter the light.

It is a metric developed by scientists in the early 20th century which determines what frequency of light our eyes are most sensitive too and how much energy is present in those frequencies.  These scientists established red, violet and blue wavelengths are very ineffective at appearing bright but colours like green and yellow are very good at appearing bright.

When selecting lighting, it’s important to choose lights with the right lumen output for your needs. For example, if you need bright light for a workspace, you may want to choose lights with a higher lumen output, while if you need softer lighting for a living room, you may want to choose lights with a lower lumen output.

Historically, the wattage number on the packaging of incandescent or halogen bulbs was a useful indicator of the bulb’s brightness. However, in 2023, with so many types of lights with varying efficiencies, relying solely on wattage is no longer sufficient. For instance, you cannot compare the brightness of a 50W halogen bulb with that of a 12W LED by wattage alone. All you can know is that the 50W bulb requires more power. A bulb’s brightness is actually determined by the lumens it emits, not by its wattage. Lumen output measures the amount of light a bulb emits, while wattage measures the amount of electrical power consumed. A bulb with high lumens will appear brighter and illuminate a larger area, whereas a bulb with low lumen output will only light up a small space and appear dull.

Efficacy

To ensure that you are buying an LED fixture that is of high quality and energy efficient, it’s essential to consider its luminous efficacy. Luminous efficacy refers to the measure of how effectively a light source produces light, and it is expressed in lumens per watt (lm/w).

For instance, let’s compare a standard 50W halogen downlight globe with a Faze Edge 110 LED fitting. The halogen bulb has an output of 420 lumens, which gives it a luminous efficacy of 8.4 lm/w. In contrast, the Faze Edge 110 has an output of 1320 lumens and a luminous efficacy of 86 lm/w, which is ten times more efficient.

To put it simply, luminous efficacy measures how well a light source converts electrical energy into visible light. A high luminous efficacy indicates that a light source produces more lumens per watt of electricity it consumes, resulting in more efficient and cost-effective lighting. By choosing LED fixtures with high luminous efficacy, you can save energy and reduce your lighting costs in the long run.

Some of the factors we don’t always consider when purchasing a new light, are directly related to the quality of the light.  Let’s discuss two common issues, glare and flicker, and how you can solve them.

Glare

Light is a crucial element in our daily lives, but it can also cause discomfort when used improperly. One common issue that people experience is glare, which is a visual sensation caused by excessive and uncontrolled brightness in the field of view. In simple terms, glare occurs when there is a sharp contrast between a bright light and a dull background.

The problem with glare is that it can cause discomfort, headaches, and eye strain, making it difficult to focus on tasks or relax in a space. Glare is often caused by downlights, which are a popular type of ambient lighting in Australian homes. The reason why some downlights are glary while others are not is due to how visible the light is coming out of the fitting compared to the light level of the surface around the light.

When a downlight has the LED/globe set deeper into the fitting, the light source is not actually visible, and the glare is reduced. For example, the Faze Edge X downlight can produce a lot of light while having a deep-set lamp position to control glare.  When a manufacturer is just using a diffuser, this doesn’t usually remove glare.

It’s essential to choose high-quality downlights that are designed to reduce glare. Cheaper, low-quality downlights are still energy efficient, but they use cheap components that cause uncomfortable amounts of glare. Make sure you choose the right balance for your project and budget.

Flicker

The phenomenon of flicker is a common occurrence in LED lights, characterised by rapid and often invisible changes in brightness that occur many times per second. Although flicker may not always be noticeable, it can have negative physiological and neurological effects on the body, such as eye strain, headaches, and reduced concentration. The stroboscopic effect or vertical streaking lines seen in photos of moving objects are signs of a flickering light source.

The percent flicker is used to calculate the relative difference in brightness between the maximum and minimum brightness exhibited during a flicker cycle. A 0% flicker value indicates no brightness flicker, while a 100% value indicates a rapid alternation between completely on and off, which is not ideal. A general rule is to aim for less than 5% flicker in any light source to avoid negative effects.

Exposure to flickering light bulbs can cause the undesired health effects mentioned above. If concerned about the presence of flicker, a simple test using a smartphone camera can determine if the LED lights are at fault.  Turn on the camera and aim it at the light in question. Look at the screen and if you see a series of dark and light bands travelling across the screen, then you have a flickering light.

The easiest solution to ensuring no flicker in LED lights is to purchase “flicker-free LEDs.” These LEDs use a quality driver to eliminate any visible flicker by converting the current from AC to DC and stepping down the voltage, providing constant current to the LED lights.

When purchasing LED lights, it is important to ensure that they are of high quality and have a flicker-free driver. A simple way to do this is by looking for “Flicker Free” on the packaging. The Faze Pro Adjustable downlight is an example of high-quality LED lights with a flicker-free driver.

We hope this guide has provided a solid understanding of the factors that influence LED quality.  Our team is ready to answer any questions should you wish to discuss further.