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What is the difference between Incandescent and LED bulbs?Updated a month ago


Incandescent bulbs emit broad-spectrum, polychromatic light (multiple wavelengths with heat from a single source). The emission is between 550-3000+nm with NO UV! This is all the wavelengths studied for light therapy and heating with irradiance proportional to the user's distance from the bulb. 

It is the tungsten filament of the bulb, when incandescing, that produces all of the bands of wavelengths in the chart below. You notice I said 'bands of wavelengths', this is because the emission includes yellow/orange/red visible light as well as the full band of NIR (700-1500nm), the full band of MIR (1500-3000nm), and some FIR (300+nm).

Our ThermaLight™ bulb in particular delivers 2x the irradiance in the light therapy (photobiomodulation) band of visible red and near infrared 600nm - 1000nm as well as more heating (over the standard heat lamp). 


They differ from incandescent in three specific ways, 

  • You need multiple little diodes (the LED 'bulb') due to their monochromatic emission, this means you do not receive the entire NIR spectrum. This is unnatural compared to the sun's emission that we are accustomed to receiving. Please click here to see our emission compared to the suns emission!
  • The spread of the light from the diode induces flicker stress. The flicker you experience from modern, electronic controlled, light sources has been shown as a nervous system stressor. Not a concern with our bulb. Click here and here for the ThermaLight™ flicker test and see how it fights flicker from other sources.
  • You do not receive any heating from LED. 

The common denominators between LED & incandescent bulbs, in respect to photobiomodulation (red + NIR), is the irradiance, wavelengths and fluence that affect the dosage and time. The modality does not alter the efficacy. 

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