I bought some of these…

http://cgi.ebay.com/Infrared-LED-Emitter-OSRAM-SFH409-2-SFH409-T1-3mm-25_W0QQitemZ170121587095QQihZ007QQcategoryZ111609QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

they looked like the same as the 489’s people have been talking about…

Will these do?  or did I just waste 10 bucks?  They are small and have a shadowy look to them (where others seem to be very clear).

Thanks!

They are a little different but should work decently. First, they’re a 3mm version, not 5mm (so they’re a little smaller). Also the wavelength is 950nm, not 880nm. You didn’t spend too much though, so I don’t think you wasted any money.

yeah, their tiny.  Now I’m considering testing them with thinner plexi and see how they work.... I wish I could buy smaller pieces for testing purposes.

Thanks for your input!

personally i dont think it really matters what leds you use, some are better then others sure, they have better performance, so instead you could use a few more of the weak ones