<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by recercare:
Cateye says their Stadium 3 (HID) is four times brighter than Halogen. Niterider says 3 times brighter, and Underwater Kinetics double as bright. This is very confusing.
HID lights are mostly used for diving. <HR></BLOCKQUOTE>
Cateye Stadium uses a different bulb than the othertwo. It has a 21W bulb which gives some 1500lm.
Niterider and Light cannon use the 10W bulb which gives about 500lm. It depends on with which halogen bulbs you compare it .-) It depends if you compare it with a bulb with 10 or with 5000 hours lifetime.
But I don't know where you got your numbers from. Cateye states that their light has an incandescent equivalent of 80+W, this is (approximately) little more than three times as much as the light's power consumption.
Niterider claims that the light consumes one third of an equivalent halogen light, which is about true (35W versus 12W). I cannot find any source where they claim four times the brightness of a halogen bulb.
UK claims to get four times (actually five times, because they include ballast efficiency) the efficiency than a 'standard' halogen bulb.
UK's higher claim couldbe explained by it's underwater use.
HID lights are mostly used for street, arena, big room and similar lighting.
Second most uses are in cars (lower medium to higher class here).
For portable lights they just hit the diver's market first because this people are used to spend $500 for a light .-)
I'm working on a caving light with the 10W bulb and looks promising. Maybe I also make MagLite 2D like flashlight (but with 8 AA cells instead), it should work some 1.5 hours on the best NiMH cells.
It's lifetime does not so much depend on working hours, more on how many times you switch it on and off.
And the bluish tint is actually closer to sunlight. If you don't have incandescents around, you will not mention it too much (at least I do, but people are different).