Originally Posted by jeff-o
OK, if I'm going to make a tail light out of 8000 mcd red LEDs, how many LEDs do you think I should use? 20? Driven at half-power it's only 10mA each, for a total of 200mA and 80,000mcd of light. Not too shabby...
Sounds good, but do you think you will get full output if you drive them with 10ma? You might consider a series/parallel arrangement to keep your battery happy. What kind of battery are you thinking of using?
An alternative is to use one or two Luxeon Stars. Each one is about as bright as twenty 5mm. LEDs, and they give you a lot of design flexibility, i.e. there are all kinds of lenses and optics available for them. But they cost about $6.25 ea. in unit quantities so this might end up being more expensive.