Quote Originally Posted by Ryuji View Post
I set up 3 orange LEDs of 625nm peak in my darkroom, and did some fogging test.
This is very useful information Ryujii. Can you supply a part number for the LED's you used ? I'm curious to know who manufactured them so I can see the datasheet. Agilent have a good reputation for small values of FWHM. However some dodgy companies who don't care about manufacturing to their published specs have much wider spectral emissions (FWHM).