What Are Full Spectrum Light Bulbs?

These days it’s easy to find some bulbs sold as “daylight temperature” or “daylight” color output. Guess what, however – that’s often not the same as a full spectrum bulb!

But what is a full-spectrum light bulb and how is it different from a regular bulb?

What is a Full-Spectrum Light Bulb?

what is a full spectrum light bulb

The purpose of a full-spectrum light is to mimic the complete natural electromagnetic light spectrum — in other words, its design leads to it looking as much like sunlight as possible. Full-spectrum bulbs use filters or other technology to create light with the same wavelength as sunlight.

Essentially, full-spectrum light bulbs are working to trick your eyes into thinking the light is midday sunlight rather than from an artificial light source. These light bulbs vary depending on the brand, purpose, and materials used. Typically, they create a soft “white” light that feels less harsh than other incandescent or fluorescent lamps.

There are a ton of practical and aesthetic reasons to use full-spectrum light bulbs. Perhaps you’re trying to grow plants indoors or in areas with limited natural sunlight, or maybe your aquarium needs natural light to keep the plants healthy. Perhaps you just don’t like the color or intensity of other lights.

In any case, full-spectrum light bulbs are a great way to bring the calm and comfort of natural sunlight into your house.

What is Full-Spectrum Lighting?

Full-spectrum lighting is simply a lighting setup using full-spectrum bulbs rather than other types of light bulbs. Using only (or a vast majority) of full-spectrum lamps creates an environment where you can enjoy daylight-like lighting in your home or other indoor space.

There are many reasons to implement full-spectrum lighting in your house, business, or in tons of other places. Many people with aquariums use full-spectrum lighting to keep their pets and plants healthy. The proper full-spectrum lighting setup can even encourage growth in underwater plants and even enhance the natural colors of your fish and marine life. However, some saltwater or coral-reef-type aquariums require blue light instead of sunlight.

Full-spectrum lighting is also very popular with gardeners, especially green-thumbed people trying to encourage plant life to thrive indoors. The proper full-spectrum lighting can help plants grow all year and even bloom in the winter. This additional growing time is possible because full-spectrum lights can produce the right color temperature to encourage photosynthesis, making for effective indoor growing operations.

What K Is Full-Spectrum Lighting?

To get a light bulb that produces as close to natural light as possible, it’s essential to find a full-spectrum light bulb with a high color rendering index (CRI) rating (90-100) and an ideal color temperature of about 6,000-plus degrees Kelvin, or 6,000K.

What Light Bulb Is Closest to Natural Light?

what light bulb is closest to natural light

The color of light is measured in degrees Kelvin, with different temperatures relating to different hues. Daylight is typically measured between 5,000 and 6,500 degrees Kelvin, while most warm, white light is estimated at about 2,700K-3,000K.

Another way to measure light color is with the CRI, which is a 0-100 scale representing how much of the complete light spectrum a light bulb can represent. While 100 is technically a perfect full-spectrum rating, most good full-spectrum light bulbs are rated about 90. A CRI score of 80 is standard for most household light bulbs.

What Technology Is Used for Full-Spectrum Bulbs?

what technology is used for full spectrum bulbs

The key to full-spectrum light bulb technology varies based on the kind of bulb; since “full spectrum” is a description rather than a technical definition, there are many different types of full-spectrum light bulbs, each with its own unique technologies.

Incandescent light bulbs in the full-spectrum range are typically made with a neodymium glass enclosure, which works to filter out some of the warmer yellow and red colors that many incandescent light bulbs produce. The filtration of those colors allows for a soft, filtered white light that more closely mimics natural sunlight. Often, the neodymium casing makes the lamps look purple when not in use.

For fluorescent light bulbs, full-spectrum lighting requires a combination of phosphors that achieve the correct Kelvin temperature scale to produce white, daylight-like light. One advantage to full-spectrum fluorescent bulbs is that their design often lends itself to accurately representing colors in alignment with the color rendering index, so these are great for reliably natural light. Full-spectrum fluorescents usually look white when lit or unlit.

Where to Buy Full-Spectrum Light Bulbs

where to buy full spectrum light bulbs

Luckily, you can find full-spectrum light bulbs almost anywhere you can buy regular light bulbs, as they are becoming more and more common in hardware stores and with online retailers. There are many options available from websites such as Bulbs.com or larger companies such as Amazon.

You can also find full-spectrum bulbs in stores such as Home Depot and other home improvement retailers. The most common place to find full-spectrum bulbs (besides specialty shops for gardeners and aquarium enthusiasts) is at a large outlet or hardware store.

How Much Do They Cost?

Because of their unique uses and abilities, full-spectrum light bulbs often cost a little bit more than the standard light bulb. You can expect to spend about $4 for an affordable 36-inch fluorescent tube light bulb or close to $10-$20 for an adjustable light from a hardware store.

There are quite a few options to buy full-spectrum light bulbs online, with many ranging around $20 for a single full-spectrum bulb. The price range does vary greatly depending on the quality and number of light bulbs in the package.

Some of the more specialized full-spectrum lights, such as those specifically designed for aquariums or indoor gardening, might be a little pricier than general full-spectrum bulbs. For example, on Amazon, you can find a premium “Sunlike” full-spectrum bulb for about $20, a full-spectrum growing light for around $16, a full-spectrum aquarium light for $40, and a set of three typical full-spectrum bulbs for $17.

The easy answer is that the price of a full-spectrum bulb varies depending on where you buy it, its planned use, and its quality.

New Research in Full-Spectrum Lighting

new research in full spectrum lighting

Recently, many people have been using full-spectrum lighting in their homes to combat the symptoms of seasonal affective disorder, though research continues to gauge its effectiveness. It has become more common to bring full-spectrum lighting into living spaces during months where natural sunlight is limited to help with environmental light stimuli and regulation of circadian cycles.

There has even been some research into whether full-spectrum lighting promotes sales, improves appetites, and enhances moods, but those studies for this are still ongoing.

Other research shows that people tend to prefer natural lighting instead of electrical lights, which could reflect a psychological association with nature that produces a positive effect. The positives created by daylight, according to some research, might improve people’s moods and motivate them more. And full-spectrum light sources provide that association with natural sunlight.

James Marshall

About the author

James is a business management professional and consultant with a former background in maintenance, repair, and hands-on projects. He enjoys DIY tasks and maintenance around the home as well as part-time writing. Read more »