Solar Meters, Dual Lens Chips and Irradiance - What Actually Matters?
Irradiance matters because more brightness = more treatment. With weaker panels, you would need to spend more time to gain the same benefits as you do with strong panels like the Hero300.
Two aspects which influence irradiance are:
Dual Lens Chips
Some brands make a big deal about single or dual chip LEDs, but we believe whether you choose a single chip/lens or a dual chip/lens panel is unimportant.
This is because most panels with dual lens LEDs have about half the LEDs, so the total amount of lenses/outputs is the same. It simply doesn't matter whether you have 300 3W single lens LEDs, or 150 6W dual lens LEDs i.e. 300 total 3W lenses within the 150 6W dual lens LEDs. The end result is the same (and what matters more is the power driving those LEDs and the resulting irradiance!).
That being said, there is one exception: Some brands will try to trick you with dual LEDs by omitting information about the bulb wattages or true output power. The reason this is sneaky is that if you have, for example, 300 3W dual lens LEDs (600 total chips) with 390W of power, you would still get the same net effect as 300 3W single lens LEDs despite having double chips in the former because those chips are split between the same (390W) power source and the bulbs are effectively only 1.5W each (3W lenses divided by 2 chips).
Metering Type
There are different types of meters which can yield different numbers. Solar meters are the most commonly used when measuring red light therapy panels because they provide large numbers which can impress prospective buyers. Despite this, we do not see solar meter measurements as a problem because they are used so consistently that they fulfill their function of allowing people to compare brands.
That being said, beware of brands with extremely high irradiance measurements because this probably means they were taken immediately in front of the panel (where you body never should be because you would be exposed to maximum EMF!) and not at safe usage distances like ours are.
The most important thing to remember is to compare panel irradiance measurements at the same distances.