Buy a few pieces of each variety, connect them to a power source, and put them behind the filter=20 to see which is the better performer. Then buy enough to finish the project. Regards, Jim > -------- Original Message -------- > Subject: [EE] Selecting a green LED > From: James Holland > Date: Mon, September 30, 2013 10:26 am > To: "piclist@mit.edu" >=20 >=20 > I'm looking to select some green LEDs for a clock that will be used outdo= ors. Looking at the catalogues I can get various wavelengths and the highes= t light output appears to be from those with a more yellow output, around f= our times that of a pure green LED. The clock has a green filter which I wo= uld guess is closer to a pure green. Am I likely to be better off with a lo= wer power pure green LED or a higher power yellow/green LED. Unfortunately = I don't have any real data, the display was removed from a clock so the exi= sting LEDs are an unknown quantity as is the filtering capability of the fi= lter so I'm really just hoping for general information based on other's exp= eriences. >=20 > Regards >=20 > James > =20 > --=20 > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .