If you have read about red light therapy or RLT (Red Light Therapy), you have likely seen the numbers 660nm and 850nm. Almost all quality red light therapy products use these two wavelengths, but for those new to the field, it is not always obvious what the numbers mean or why they are important.
The short explanation is that 660nm is visible red light while 850nm is near-infrared light which is just outside the human field of vision. Both are used in modern red light therapy and are often combined in the same panel to create the most complete treatment possible.
What does nm mean?
First we need to figure out what nm actually means.
nm stands for nanometer, which is a unit used to measure the wavelength of light. Different wavelengths are perceived as different colors by the human eye.
When it comes to red light therapy, wavelengths within the red and near-infrared range of the light spectrum are primarily used.
| Wave-length | Type of light |
|---|---|
| 660nm | Visible red light |
| 850nm | Near-infrared light |
What is 660nm red light?
660nm is the red light that you clearly see when a red light panel is on. It is also the wavelength that many people associate with red light therapy because it gives the panel its characteristic red glow.
When you look at a red light panel, it is primarily the 660nm lamps that are clearly visible. This is why many people experience the entire panel as glowing red even when it is also emitting near-infrared light.
660nm is used in basically all modern premium products for red light therapy and is one of the most established wavelengths in the field.
What is 850nm near-infrared light?
850nm works a little differently.
The light is just outside the human field of vision, which means you don't see the same red glow as from the 660nm lamps. Many people who use red light therapy for the first time therefore believe that some lamps are broken or not working.
In reality, the lights work exactly as they should.
If you look closely in a dark room, you can sometimes sense a very faint glow, but in normal use, the 850nm light is often perceived as invisible.
This is also why many quality products combine both visible red light and near-infrared light in the same panel.
Why are both wavelengths used?
The most common question we get is why modern red light panels use both 660nm and 850nm instead of just one wavelength.
The reason is simple.
By combining both wavelengths, the user has access to both visible red light and near-infrared light in the same treatment. This is why almost all professional panels today use both wavelengths simultaneously.
This is also the reason why all models in Infracenter's PRO MAX series are equipped with both 660nm and 850nm.
Why do some lights appear to be off?
This is undoubtedly the most common question from new users.
When you start a panel that uses both 660nm and 850nm, the red lights will shine clearly while the near-infrared lights may appear dark.
That doesn't mean they're broken.
The 850nm light is outside our field of vision and continues to be emitted even if you cannot see it with your eye. This is completely normal and a sign that the panel is working properly.
What wavelengths do Infracenter panels use?
All panels in the PRO MAX series use both 660nm red light and 850nm near-infrared light.
| Model | Wavelengths |
|---|---|
| IT300 PRO MAX | 660nm + 850nm |
| IT900 PRO MAX | 660nm + 850nm |
| IT1800 PRO MAX WIDE | 660nm + 850nm |
The difference between the models therefore does not lie in the wavelengths but in the treatment area, size and how large parts of the body you want to treat at the same time.
Which panel should I choose?
If you primarily want to use red light therapy for the face, neck or smaller treatment areas, the IT300 PRO MAX is an excellent choice.
For back, shoulders, legs and larger areas, we recommend the IT900 PRO MAX, which for many is the most versatile model in the series.
If you want maximum coverage and the largest possible treatment area, the IT1800 PRO MAX WIDE is the obvious top model.
Summary
660nm and 850nm are the two most common wavelengths in modern red light therapy and are used in most professional red light panels.
660nm provides the red light that is clearly visible to the eye. 850nm is near-infrared light that is just outside our field of vision and therefore can appear invisible even though it is working properly.
It is the combination of these two wavelengths that has made them the standard in modern RLT (Red Light Therapy) and therefore Infracenter's PRO MAX series also uses both wavelengths in all models.
FAQ
Is 660nm or 850nm best?
Most modern red light panels use both wavelengths simultaneously, so it is common to combine them rather than choosing one or the other.
Why don't the 850nm lights appear to be glowing?
850nm is near-infrared light which is outside the human field of vision. The lamps will still work even if you don't see the same red glow.
Do all Infracenter panels have both 660nm and 850nm?
Yes. All models in the PRO MAX series use both wavelengths.
Is 850nm UV light?
No. 850nm is near-infrared light and has nothing to do with UV radiation.
Which panel should I choose?
The choice depends mainly on how large an area you want to treat at the same time. The IT300 is suitable for smaller areas, the IT900 is suitable for most users and the IT1800 PRO MAX WIDE offers maximum treatment area.