Bulbs that generate light close to sunlight
Introduction
In this article we look at what light bulbs are similar to sunlight.
Firstly we look at the benefits of sunlight. Secondly we discuss the spectrum of light the sun provides.
Then we look at what standard bulbs are closest to sunlight. Finally, we provide a couple of recommendations that you can buy in your local store.
What are the benefits of sunlight?
There are a many benefits to direct sunlight for our bodies and minds.
These include:
- Improving your sleep. Our bodies produce a hormone called melatonin that helps control our sleep patterns. Melatonin does not actually put you to sleep, rather it puts us in a state of relaxed wakefulness that promotes sleep. The body starts producing melatonin once it gets dark and we feel sleepy around two hours later. Exposure to bright natural sunlight in the morning tells our bodies to stop producing melatonin and wake up. Also starting our internal body clock for the day.
- Reducing stress. Studies have shown that melatonin can also improve symptoms of anxiety such as stress. Sunlight at the correct time is essential to correct melatonin levels. So sunlight helps us regulate melatonin and possibly reduce stress. Additionally researchers at the University of Edinburgh have found that sunlight exposure releases nitric oxide that can help reduce blood pressure.
- Reduce our body mass index. A study from Northwestern University suggest that exposure to bright light in the morning can help reduce our levels of body fat.
- Healthy bones. When sunlight shines on our skin our bodies produce vitamin D from cholesterol. Given that vitamin D regulates our bodies production of calcium and phosphate. And that these nutrients keep bones, muscles and teeth healthy. Thus sunlight and vitamin D ensure our bones stay healthy. In addition, vitamin D is linked to strengthening our immune systems.
- Killing bacteria and better air quality. The ultraviolet part of sunlight kills off potentially harmful bacteria and improves indoor air quality.
- Helping with depression. As well as triggering the production of melatonin sunlight also boost the bodies levels of serotonin. Seratonin is considered a natural mood stabilizer and helps reduce depression and anxiety.
Obviously too much sunlight is not good for us either. It can lead to sun burn, long term skin damage and skin cancer.
What spectrum does sunlight provide?
So, now that we understand the many benefits that come from exposure to natural light the next question we need to ask is what is sunlight actually producing? When we see a rainbow after a rain shower this is sunlight splitting the light up into its component colors. Due to the water droplets in the air acting like lots of tiny prisms.We see these wavelength bands as different colors. This range of colors is known as a spectrum (science’s version of a rainbow).
The spectrum for sunlight starts with red light, which has a wavelength of 700 nanometers (a nanometer is one thousand-millionth of a meter). Next comes orange, yellow and green and finally blue and violet, at around 400 nanometers. This is known as the visual spectrum of light.
In addition to the visible colors, the suns light also contains wavelength of light that we can’t see. For example, infra-red at the top end and ultraviolet at the bottom. As well as X-rays, gamma rays and radio waves. This non-visible light is called the electromagnetic spectrum of the sun.
Sunlight it pretty regular across the spectrum providing the same level of red to blue and only dipping a little in the violets. In the evening the violets, blues, greens and yellows become muted and the oranges and reds predominate. This continues at night were the red light is dominant.
What spectrum do light bulbs provide?
There are four main technologies used in the light bulbs we buy in our stores.
Incandescent – These are the old style light bulbs with a wire filament. When a current passes through it the filament glows brightly generating light. They waste a lot of power generating heat rather than light making them very inefficient.
Halogens – Like incandescents halogen bulbs have a filament that glows when a current passes through it. The difference being that the element surrounding the filament contains only halogen gas. The gas increase the light produced and also extends the life of the filament.
Compact Fluorescents – or CFLs are fluorescent tubes, like the ones used in offices and stores. The manufacturing process folds the tubes into a compact shape so that they fit in a normal light bulb socket. Light is release when a current passes through the mercury vapor within the sealed tube.
LEDs – Light Emitting Diodes are small pieces of semiconductor that emit a light when a current passes through them. Within an LED light bulb there are 3 separate LEDs, one red, one blue and one green. These three different colors of light combine to produce a white light.
What light do they produce?
Incandescents produce a warmer red/yellow light that is close to natural light in the evening.
Halogens produce high green, yellow and red light which is close to natural light but missing the blue component.
Compact fluorescents produce two peaks one in green and the other in orange.
LEDs vary depending on the type bought. Several brands market LEDs bulbs that produce a range of lights. For example:
- Warm white (2700 – 3000k) provides a peak in the red band
- Cool daylight (5000k) has a reasonably flat color profile with peaks in red and green
- Bright daylight (6500k) is again reasonably flat with slight peaks in blue and green and a tailing off of red.
So which is the closest light bulb to sunlight?
So which is the closest light bulb to sunlight
As we saw above LEDs are far more flexible in the way they create their light. In addition to fixed light LED bulbs, there are also smart bulbs that allow you to tune the white light. Phillip, GE, Feit and Geeni all produce well regarded smart white light and color tunable light bulbs.
Also, a Korean LED manufacturer now produces an LED with a purple emitter rather than the normal blue. Consequently, the blue peak in normal LEDs is reduced giving us a light output closer to sunlight.
Taking this all into account, we have picked out two reasonably priced light bulbs who provide a fairly good approximation of sunlight. Originally we had a Smart bulb on our list but the CRI (see below) for the bulb was not too good so we couldn’t recommend them as being close to sunlight.
Color Rendering Index
Or CRI. Before we discuss the best light bulb let’s talk about the color rendering index. To explain, when artificial light reflects off a colored surface the color we see is different from what we would see under natural light. So, we rate the color under natural light as 100 and the color under artificial light as less than 100. In effect the lower the CRI the less the color look natural. On the other hand the higher the CRI the closer the light is to natural light. In conclusion, as we want a light close to sunlight, for us the higher the CRI the better.
Best Overall
Not only have GE been in business since 1892 they are also the most popular brand here in the U.S. Firstly, their sun filled LED brand uses the SunLike Series LEDs we mentioned. Consequently producing a light bulb with a color rendering index (CRI) of 97 which is excellent. Additionally, GE also claim that the bulb cuts out the blue light peak which can keep us overly wakeful in the evenings meaning the bulb can be used all day. In conclusion, a lot of plus points for not too much money.
Fact sheet
- Rating: 4.5 stars out of 5
- Price: Around $7.50 a bulb if bought individually
- Wattage: 60 watt equivalent / 10.5 watts actual
- Lumens: 850
- Light Range: Daylight (5000k)
- Lifetime: Rated to last 15,000 hour (13 years based on 3 hours per day use)
- Warranty: 5 years
- Dimmable: Yes
- Indoor/Outdoor: Indoor use only
Best Budget Option
Feit have been in the lighting business for more than 40 years (since 1978) and are a family owned and operated business out of Los Angeles. Their enhance range of bulbs claims a 90+ CRI meaning that they provide light pretty close to that of sunlight. What’s more these light bulbs only cost a little over $3 each. Additionally they are rated to last 15,000 hours and are Energy Star certified.
Fact sheet
- Rating: 4.7 stars out of 5
- Price: Around $3.25 a bulb if bought in a 4-pack
- Wattage: 100 watt equivalent / 17.5 watts actual
- Lumens: 1650
- Light Range: Daylight (5000k)
- Lifetime: Rated to last 15,000 hour (13 years based on 3 hours per day use)
- Warranty: 5 years
- Dimmable: Yes
- Indoor/Outdoor: Indoor use only
Sources
We are thankful for the information below that allowed us to decide what light bulbs are similar to sunlight.
Timing and Intensity of Light Correlate with Body Weight in Adults
Innovative SunLike natural, full spectrum LEDs by Seoul Semiconductor