Hello everyone, My issue is regard a conversion from lumens to ~photons or energy at varying wavelengths. I am trying to find a way to determine the amount of energy an led can emit at different wavelengths. I figured because E = (h*c)/λ all I would need is to determine an photon emission. Most of the data sheets give Lm/W and the viewing angle. I know that Cd = Lm /(2π(1-cos(θ/2)), but thats as far as I got. I need a definite way to calculate the theoretical energy being emitted at different wavelengths. If anyone can help me finish what I started or help me discern a better way of find this it would be much appreciated. Also what would I do for wavelength out of the visible spectrum? For most UV or IR leds I have mW/sr @ mA, viewing angle and the basic electrical properties.