I'm confused about what you're trying to achieve... On Wed, Jul 21, 2010 at 1:13 PM, RussellMc wrote: > but LEDs look more > attractive overall. So why not LEDs? > Brightness control is desirable. A definite plus for LEDs. > 100+ lumen / Watt (exceeded only by the best LEDs so far). Well yes, but the "best LEDs" are readily available. > Capital cost: Lower lumen/$ than LEDs. I presume you mean lower $/lumen - should be fairly straightforward for higher lumen applications > Lifetime cost - give LEDs a run for their money. That's rather more difficult, unless your usage is low enough that HID bulb failure isn't an issue. Of course if you want 3200lm, then you'd need multiple LEDs - even multi-die ones won't get near that. This will give you various problems, including cooling and focusing (due to lower surface brightness / larger illuminating area). I wouldn't comment, but you seem to be comparing what you're doing with LEDs. Chris -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist