Secondary Focusing Lenses in LED Therapy Lights - Which is Best?
Lately there seems to be a good amount of confusion surrounding the concept of the secondary focusing lenses that are now commonly used in LED therapy lights. 30 degree? 60 degree? 90 degree? What is this thing, what does it mean to me and which is best?
First, it’s very important to remember what we’re dealing with at the heart of the matter: Light. That’s it. Simply light. When we create LED therapy lights, we’re creating a device that emits the highest amount of focused, specific wavelength light over a given area. Our goal is to deliver the most amount of this light over the greatest amount of area.
Unlike a traditional incandescent light bulb, LEDs have a very specific pattern in which they emit light. Whereas a light bulb emits light from all sides of the bulb, LEDs emit light in a more focused pattern much like a flashlight. However, one problem about how the light is emitted from LEDs is that even though the light is emitted in a focused pattern, its not being emitted evenly over the area due to the nature of the construction of LEDs. This means that within the output, you still do not have a perfectly focused, clean emission of light as its much more concentrated in the middle of the output than the sides of the circle.
With over 10 years of vast experience designing and manufacturing high power LED panels for various applications - more than three times the amount of any other LED therapy light company on the market today - PlatinumLED was the first manufacturer back in 2010 to utilize what are now known as “secondary focusing lenses” to solve this light emission problem and emit light from LED panels in a perfectly mixed and controlled format. This technology has now been widely adopted throughout the LED industry and this is why there are now other lights that may look similar to ours but still never capture the full technology our power that an authentic PlatinumLED light possesses.
So, what is this secondary lens, what does it do and how does it work? A secondary focusing lens is a small piece of transparent acrylic, formed in a very exact shape that sits on the top of the LED to gather the light emitted from the LED and re-emit this light in a perfectly mixed, shaped form. The lens is able to accomplish this by its shape and the way that the light bounces within it before exiting the front of the lens, much like a prism. There is no magnification happening as with a magnifying glass, but a simple gathering of light and re-emitting the same light in a perfectly even form.
Not only are we able to emit the light in an even manner, we’re able to control the angle of this beam of light to focus it tighter with more centralized intensity or wider for more coverage in the exact same manner as a focusing flashlight. In fact, we can use the concept of an adjustable focusing flashlight to think about how these lenses work. The wider the angle of the beam, the greater the coverage but the less overall intensity due to the light being spread out. The tighter the angle of the beam, the less coverage but greater spot intensity due to the light being concentrated in one area. Remember that you are not increasing the overall amount of light that’s being emitted, but simply focusing the light in different angles. This is the exact, same thing that is being accomplished by these secondary focusing lenses.
For the sake of precision, we now standardize these lenses by the angles that the light is emitting from the lens and this is where the different degrees that you’ve now heard of come in to play. The 3 main sizes typically used are either 30 degree, 60 degree or 90 degree. So which one of these is the best and why do you want it?
Before we go any farther, it’s very important to note that there is a HUGE variance in the actual light outputs of various LED devices and this is due to the quality and types of components used to build an LED panel. The vast majority of LED therapy lights on the market today are built using very cheap components that do not emit the same level of light that a higher quality, professional grade LED panel will emit. Just because two lights may consume the same amount of wattage, this does not mean that the actual light output is the same and this light output is the most important factor of any. This is why the actual amount of light being emitted must be measured by a solar power meter directly under the light as this is what your actual body is seeing.
Since most LED therapy lights are very under powered, they compensate for this by using a tighter beam angle lens in typically a 30 or 60 degree fashion. While this may increase the spot intensity directly under the light, this also decreases the coverage area of the light. Remember from our earlier flashlight example that this does not give you any more light, but simply focuses the same light in a more concentrated, smaller pattern. Up until very recently, high power LED therapy lights were simply not available to the average user and thus, virtually all lights used a 30 or 60 degree lens to help boost their output. This is why many "tests" and papers have been written using lights that utilize these lenses: Because that's what was available at the time of writing.
Thanks to the level of internal components used and the many years of LED manufacturing experience, PlatinumLED is able to deliver an ultra-high power, clinical level LED therapy light panel to the home user. Since this source light is very powerful to begin with, we’re able to utilize the wider 90 degree lens to deliver greater coverage and yet still retain superior light output at the end destination. This greater level of intensity yet still retaining superior coverage is the most important factor as again, we are simply dealing with light and getting as much light as possible to the greatest amount of area.
Thus, to finally answer the question of which lens is best, the answer would be the lens that gives the most amount of light over the greatest amount of area.. and installed in the LED therapy light that gives you all of this at superior levels.