1 LED = 1000 Lumens!

Did they claim same output as 1200w hmi on their site? Time for the mythbusters to check this out ;-).

Okay, so lets look at a 1200w HMI arrisun par on the arri website:

http://www.arri.com/prod/lighting/06_photometric.php?swid=L1.77570.B

About 369,000 lux output at 3m.

Back to our new product here. If their product draws about 80w based on what I saw in the spec sheet (which J was so kind to provide!), and there are 24 LEDs in the device, I would say that each LED must be in the 3 to 4 watt range. Right?

Let's switch to lumens so we can do LPW calcs--it's easier. A 1200w HMI bulb puts out about 110,000 lumens. The LPW on a bulb like that is about 86 which is normal. Very few technologies even get above 100 LPW and most are well under 100 LPW.

So, if we compare just by lumen output of a 1200w HMI bulb: Divide 110,000 by 24 and that means that each LED would have to be putting out about 4580 lumens each. Divide 4580 by 3.5w gives 1308 lumens per watt per bulb.

See, the math doesn't add up on that one. So we're missing something somewhere.
 
>Did they claim same output as 1200w hmi on their site?

Nah, that's just what it looked like to my eye (didn't bring my meters to the show). Bright enough to fill in full sun at about 10'. Also very well built.
 
I'm frankly surprised there haven't been more products for video / film lighting using these 3 to 5 watt LED spots. Lots of outdoor floodlight products coming out using those that I see at industrial lighting shows over here. It's pretty easy to use those and not too hard to put something together like this pictured product--there is heat though...
 
You're right Richard, it is pretty easy. I found an Mr-16 12volt bulb that has (3) 3 watt cree leds. I put 4 of them in a housing and drive it with a small 12 volt battery. Eash bulb puts out 240 lumens. I really like it for on and off camera.
Gary
 
Cool Lights said:
... It's pretty easy to use those and not too hard to put something together like this pictured product--there is heat though...
Click to expand...

Exactly, Richard. The heat is a real issue on those things.
We're experimenting with the LUXEON REBELS in the 3x config, and are making a MINI LED light using one of them, but the same thing applies: they are little heaters!
 
The new Rebel 100s are pretty impressive... and tiny! I've got a flashlight that uses it and that thing can throw some lumens.
 
For those of us who are guerrilla based (or just poor), there are LED's like these.

Quite a bit of light there, all things considered. The throw isn't very far, and it's no 1200 watt HMI, but I'm a little surprised I don't hear many low-budget indie projects using lights like this.
 
snowleopard said:
For those of us who are guerrilla based (or just poor), there are LED's like these.

Quite a bit of light there, all things considered. The throw isn't very far, and it's no 1200 watt HMI, but I'm a little surprised I don't hear many low-budget indie projects using lights like this.
Click to expand...

Yes I've seen quite a few of those worklight type solutions. It's particularly nice when they have batteries on them so you don't have to go searching for that which can be tough to rig up. The thing that concerns me with the vast majority I've seen is they are all too blue. It's such a challenging thing to get real 5600K hand selected LEDs that are all consistent with each other in output and quality. It's very easy to find the cheaper kind.
 
Gary said:
You're right Richard, it is pretty easy. I found an Mr-16 12volt bulb that has (3) 3 watt cree leds. I put 4 of them in a housing and drive it with a small 12 volt battery. Eash bulb puts out 240 lumens. I really like it for on and off camera.
Gary
Click to expand...

I think it's best to stick with the (harder to find) 12v (or DC in general) models, they are so much easier to adapt to batteries and to fashion a dimmer for should you want to. Plus, as long as you keep the PWM in the dimmer circuit pretty high there should be no flicker. For some reason they're coming out with most of these things that operate off of AC line voltage and while that may be a convenience for consumers that want to replace conventional light bulbs, its not so great for our uses.
 
vidled said:
Exactly, Richard. The heat is a real issue on those things.
We're experimenting with the LUXEON REBELS in the 3x config, and are making a MINI LED light using one of them, but the same thing applies: they are little heaters!
Click to expand...

When can we see pics? ;-)

What is the wattage of the unit? About 2w perhaps per LED?

The thing I think most don't realize about LEDs is that as the wattage of the unit goes up so does the heat. That's just normal with anything drawing power. But surface area emitting the heat comes into play to trick people into thinking that one source is cooler than another.

On a 5w panel where the LEDs are distributed as many small wattage devices, so is the heat output and thus the perception is that the unit isn't so hot. However on a single 5w LED, or any point light source, the heat output is concentrated in one single area so is very intense. There is no natural heat sink or radiator unless you add one. Hence, why a 200w (actual wattage) fluorescent bulb seems cooler than a 200w incandescent bulb. They're both putting out roughly the same amount of heat but the surface area emitting the light (and heat) is so much larger on a Flo, so the heat output is spread over a larger area and is therefore not so intense. HMI's have the same problem and even worse and the fixture is treated as a big heat sink for the bulb in order to make sure it lives its normal life.
 
It's actually pretty decent. The color temp is also a bit warmer than most of the LED flashlights I've used. This flashlight has several modes. In the lower output modes, it shifts toward purple. I don't think that it's a problem with the emitter as much as it is a problem with the driver circuitry.
 
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