Can someone explain to me what is the wavelength of body heat? Since visible light is between 400nm - 700nm. Is body heat wavelength above 700nm? What is the wavelength range of body heat in respects to nm or m? And lastly are Infrared cameras made with Avalanche Photo Diodes? like the one attached? http://www.lasercomponents.com/de/?...nsreport/avalanche-photodiodes.pdf&no_cache=1 Also i have a question about current arcing. Since arcing is visible would a avalanche photo diode be suitable for visible light as well?