High CRI desk lamp: why does the color rendering index matter in choosing the best desk lamp for your home office?

US Government census data reveals that more than 8 million people work from home in the USA. If your work environment needs lacks light, it could lead to a lot of issues like not being productive or having trouble with your eyesight. One solution to this issue is to look for a desk lamp with high quality light output.

The highest quality light is pure natural sunlight, but newer LED lamps are improving at replicating natural light. Manufacturers measure this through a metric called CRI (Color Rendering Index), and you want to look for a desk lamp with at least 90 CRI (pure sunlight is 100) to ensure your documents are easy to read and photos don't look washed out.

How does the color rendering index relate to lighting? Good question. This article will examine what a good CRI rating is for LED lights. We'll also provide home office situations where high CRI is critical. In a few short three minute reads, you will learn why the color rendering index is the second most crucial specification in buying a perfect desk lamp for your home or office space.

Ready to get started?

If you have noticed that things look different in a store with fluorescent lights compared to a store with incandescent or halogen lights you are on the right track. Diamond stores use specific lighting to make their jewels and watches look glamorous, while old Kmart stores used inexpensive fluorescent lighting that made everything look a little green.

When LED lights first came out many made a room look "bright" but might also look a little "washed out." This is why CRI or color rendering index is the second most crucial element in selecting a perfect desk lamp. This index is a simple and helpful lighting spec to predict how correct the visual output of a lighting product will be. The metric is a number between 0 and 100 used to predict how well a product renders color. The closer to 100, the better or more accurate colors should look under its light.

The CRI value of a light source indicates its ability to make colors look natural. Low values cause unnatural tints and hues to appear, while high values more accurately reflect the color you're trying to produce. It's essential not just for how each color looks but how it makes people look when they stand under the light source.

Our eyes have incredible color sensitivity, which is why we have camouflage military uniforms and why our ancestors could spot a lion hiding in the grass early enough to escape. In nature, your eyes see color reflected from objects. For example, a ripe strawberry reflects the red wavelength of light but not blue. However, if you look at it under an LED light that doesn't have a full spectrum of red light, the strawberry may look sickly or pink even if it is a perfect specimen.

The higher the CRI number, the better. A CRI of 80 and over is considered good, and a 90 plus rating is considered excellent. CRI numbers on a light fixture or bulb are like how well you studied for an exam: 80s are Bs, 90s are As.

Does color temperature affect CRI?

CRI isn't related to color temperature. These two things are different, and we can use an example to prove it. For instance, a 5000K daylight-like fluorescent light could have low CRI of 75, but another one could have high CRI at 90.

CRI and brightness: the perfect combination

For lighting companies to enable consumers to differentiate between high quality light and cheap ones that wash out colors, CRI is a useful indicator. Because the light coming from the sun reflects all the colors we can see, it has a CRI of 100. Today, by mixing and arranging different colors of LEDs, a good desk lamp can achieve over 90% of all colors found in sunlight.

To avoid buying a "bright" desk lamp that makes everything look pale and washed out you want to look for a desk lamp with a CRI of 90 or above. However, there are lighting products that are very bright, yet score low on the CRI due to poor color handling. You want a product that combines both high brightness and color accuracy. 

You need a high CRI rating for your desk lamp as it’s essential when working with detailed graphics design, while maintaining great home office lighting, and when long term eye care is a priority. In other words, for everyone who requires a monitor to do their work. 

Working with graphics

If you do any work with pictures, advertisements, or graphics, you need a 90+ CRI lamp. Red light is essential in rendering natural skin tones, especially in hair color or cosmetics. Flesh tones in computer-generated and printed images are susceptible to CRI fluctuations and look completely different under two different desk lamps.

If you want a good looking office

If you worked on ensuring that your office is color coordinated, or if you have visitors to your working area, you want a 90+ CRI light. For example, if you're going to make that cherry wood fancy executive desk look great, match it up with a desk lamp with 90+ CRI, and you will see every line and color variation in your work surface. Match it with a low CRI $20 desk lamp, and the same desk may just look like something from a thrift store. 

You care about your eye health

Another benefit of 90+ CRI desk lamps is that they also come with additional advanced features, such as a flicker-free driver that eliminates annoying LED flickering and automatically adjustable light levels that keep the lamp from getting too bright when the room gets darker, such as at dusk. BenQ ScreenBar and e-Reading lamp have these advanced features and avoid monitor glare. Find out more in this review. 

If you are looking at desk lamps for your home or work office space, check out the BenQ ScreenBar Plus desk lamp with its innovative design that rests above your monitor and has a CRI of 95. For a more traditional desk lamp design, the BenQ e-Reading lamp is one of the fastest-growing desk lamps in North America. With its innovative head that keeps light off the monitor and on your desk, it covers over 30% more space than a typical desk light and has a CRI of 95. Here’s more info if you’re interested. 

How is CRI measured?

To test CRI, we can setup several color patches with precisely known colors. We then use a spectrophotometer to measure the color of these patches under a light source. This process allows us to measure the color of the light reflected from it.

What is the difference between lumens and CRI?

Luminous output, measured in lumens, describes the brightness of a light source. CRI uses natural daylight in its calculation. A higher CRI indicates that the light spectrum resembles natural sunlight, while a lower score is more like or halogen/incandescent light sources.

What happens when the color rendering index is low?

We must remember that light sources with a color rendering index below 70 alter our color perception. Light sources in this category include fluorescent tubes, also known as industrial white tubes.

What is the best brightness for a desk lamp?

Around 450 lux with a 6W to 9W LED bulb is excellent all-round brightness.