LED spotlight (searchlight) - 1 million candlepower?

[NickBose]

Is this really bright?
http://cgi.ebay.com.au/ws/eBayISAPI...ndexURL=2&photoDisplayType=2#ebayphotohosting

Where can I buy this type of LED spotlight - must be very bright, powered or charged with cig lighter plug, and to be used within 15 - 25 m range?

Dealextreme and kaidomain don't carry these types of light

Also, is there a way to convert candlepower (candela) into lux?

 

[Curious_character]

The 1,000,000 candlepower is marketing hype, and probably much greater than the light will actually produce.

One candela (aka candle or candlepower) produces an illuminance of one lux at a distance of one meter.

c_c

 

[lctorana]

This is baffling.

(I have the equivalent halogen "1 million candlepower" spotlight in exactly the same case. It is seriously bright - so bright it give me the giggles. It has a 6V, 55W H3 halogen globe and a 6V, 4Ah SLA battery. No wonder it is so bright! The reflector is nothing special, but everything else about it is very good. Claimed runtime is 20 minutes, which seems about right.)

OK - let's assume that the case is the same, so the same battery, switch and charger is used as the halogen version.

What is baffling is how you can get 1,000,000 candlepower (or at least as much light as the 55W halogen with a 4" reflector) out of 12 x 15Cd LEDs.
I have a torch with 28 x 15Cd LEDs and it frankly can't outshine a 1W Cree.

But let's do the maths. Assuming that the battery is the same at 4Ah, (and assuming resistor-fed direct drive for ease of calculation) the claimed 24-hour runtime gives us a current draw of one-sixth of an amp.
And with 12 LEDs, each LED must be drawing 1/72 of an amp, or about 14mA each.

Now, being as optimistic as possible, if there is a 100% efficient DC : DC converter installed, then we can multiply that current by 6.3/3.5 to get about 24mA per LED. Still nothing special.

I would expect this torch to be somewhat underwhelming.

Am I wrong?