visable leds

[stein09163]

Things seem to be changing when describing the power of a led; so can someone tell me how i can relate (mw/cm2) to mcd. Many now are using mcd instead of nw/cm2. example: 1600nw/cm2 and 2700mcd........which has the higher irradiance when using a 660nm visable led

 

[JustAnOldFashionedLEDGuy]

Lots of instructions on the web for this calculation, so I won't repeat it, but they are not "now" using nw or mw, they always have for light sources that are not used for illumination. 660nm is not typically used for illumination, it is used for horticulture. Ditto with blue LEDs targeted at horticulture, UV, etc.