What is the difference between a hand-held LED device and a LED panel-type device?
This is one of the most confusing and most misleading area of LED technology. The most important thing to remember here is the farther the light source is from the skin, there is less light intensity at skin level which means, an ineffective treatment. It does not matter how many LED diodes there are. You can have a hundred LED diodes, but if the panel or device is even 1 inch or 2 inches or more from the skin, you are going to get less light energy at the surface of the skin. As you hold the LED device farther from the skin the light becomes more diffused and less powerful at skin level. The reason for this is that LEDs are not collimated like a laser beam. With a laser, the light is the same intensity from the source to the skin level. It is absolutely essential to have the LED at skin level for results. One of the ways to determine the light output of a light source is with a light meter. You can measure the light output at the source— at the LED diode itself, and you can measure
