Phil Rhodes
Well-known member
A 400W HMI equivalent LED would, assuming no fundamental advances, need to be roughly a 400W LED.
Aputure COB 120t First Look. Tungsten 1.5K watt equivalent one source LED fixture
- Thread starter Erik Naso
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MattinSTL
Sound Modulator
As HMI is roughly 4x as efficient as tungsten... you're probably right... although a Jab Hurricane is 187w and very nearly matches an 800... so...? Maybe that only applies to a COB design(?)
That's why I said the world would beat a path to Aputure's door if they could make a 400w HMI equivalent... but yeah... you're probably right, that it's highly unlikely. Unfortunately the Jab's have a poor TLCI... but at least for news... it doesn't even matter... the raw horsepower of the light is what makes the shot. I can't stress this enough... they are STUNNING to behold (at night)... in the day, competing with Mr. Sun... it takes stupid power. The least you want is roughly an 800w HMI... so the Jab works... but for NBC Nightly... there were TWO of the BIG Aadyntechs... the ones that make even the Hurricane look small.
So anyway... you make a good point about HMI... but my frustration about specs is still peaking... as the claims are so stupid high right now, and they don't have to be... it's like they're aiming these pitches at people who have zero experience with set lighting. Do you have an Arri 650w or similar? I'd love to hear what you see putting them side-by-side... even if you opened the glass (as if you were going to replace it) and compared a raw bulb to raw LED (w/o reflector). I have an Arrilite sitting on a shelf... as well as a few 300w Arris... totas, etc. I can't wait to dump all this tungsten... but now I have to wait until I can do some comparisons, just to see how far off the new light claims are. I WANT them to be awesome... but making statements that miss by HALF? Jeez... are they even testing these claims?
Phil Rhodes
Well-known member
By 800, I assume you mean an 800W HMI. This could only be the case assuming very different optical engineering in the two devices. Comparing the output of a (flexible but highly inefficient) ellipsoidal with an (efficient but fundamentally fixed-behaviour) PAR would make the PAR look far more efficient even if they both used the same light source.
Current HMI and LED (and fluorescent) have more or less the same luminous efficacy, with LED perhaps beginning to slide very slightly ahead in some cases. Most observable differences will be caused by the different optical behaviour of the devices in which these light sources are used. There are often very considerable differences, after all, because an HMI is a (roughly) spherical radiator which requires a reflector, whereas an LED chip has a complex emission pattern which needs to be handled, in the first instance, by the module into which it's built, and then by the lamphouse of the final device. It's very difficult to make absolute comparisons.
Now, that's not to say that in some cases the way an LED behaves might not actually be better for specific applications, and it might be reasonable to describe the LED as more efficient in that case even if it doesn't actually push out any more photons per watt than an HMI. Fundamentally, though, there is no significant efficiency offset. #
There are some fairly specific things LED has enabled - efficient tungsten-balanced light, for one. Filtering an HMI to tungsten is inefficient. Tungsten itself is very inefficient. Tungsten LED is much more efficient than either approach. Otherwise, though, if you want hard daylight there's HMI, or if you want soft light, either tungsten or daylight, there's fluorescent, and both of these technologies have existed for decades.
You can claim some unique benefits for LED, such as physical toughness, but overall the idea that LED has changed the world is misguided. The availability of lots of low-cost lighting options has more to do with the rather abrupt emergence of a surge in low-end filmmaking, perhaps provoked by DSLR video, than anything else.
And yes, ludicrous claims are irritating, but at least they're usually pretty identifiable.
P
"[...]You can claim some unique benefits for LED, such as physical toughness, but overall the idea that LED has changed the world is misguided. The availability of lots of low-cost lighting options has more to do with the rather abrupt emergence of a surge in low-end filmmaking, perhaps provoked by DSLR video, than anything else.[...]
I don't know about "unique", but as I see it, there is more to the popularity of LEDs - "physical toughness" is not so much an advantage of LEDs, but more the fact that fluorescents are actively fragile, tungsten/hmi is extremely hot, which makes LEDs easier to handle, and above all else - at least from my point of view - the biggest reason I like LEDs is that I can have them battery operated and not have to rely on generators or the mains. Now, with some of the more powerful LEDs the "battery" solutions are approaching the impractical and certainly very costly - and arguably are equally available at that level for fluorescents - but I think for most indie shooters the lower end of LEDs (even the on-camera small ones) are attractive because of how portable they are - tougher than fluorescents and battery powered. And LEDs are still in their rapid development stage where you can see more progress on the horizon, whereas nobody thinks that fluorescents or incandescents tungsten or HMI or whatnot is still developing much. LEDs are the future (at least for now, until something better comes along). YMMV.
I don't know about "unique", but as I see it, there is more to the popularity of LEDs - "physical toughness" is not so much an advantage of LEDs, but more the fact that fluorescents are actively fragile, tungsten/hmi is extremely hot, which makes LEDs easier to handle, and above all else - at least from my point of view - the biggest reason I like LEDs is that I can have them battery operated and not have to rely on generators or the mains. Now, with some of the more powerful LEDs the "battery" solutions are approaching the impractical and certainly very costly - and arguably are equally available at that level for fluorescents - but I think for most indie shooters the lower end of LEDs (even the on-camera small ones) are attractive because of how portable they are - tougher than fluorescents and battery powered. And LEDs are still in their rapid development stage where you can see more progress on the horizon, whereas nobody thinks that fluorescents or incandescents tungsten or HMI or whatnot is still developing much. LEDs are the future (at least for now, until something better comes along). YMMV.
MattinSTL
Sound Modulator
I bought some LitePanel Inca's off eBay... they arrived today. Supposed to be 650w Arri equivalents... well... as I feared... they are 300w Arri equivalents... better in some areas, worse in others, and BIG CASE... plus fans... *ugh*... disappointed. I was hoping they'd be somewhere between the 300 and 650... nope... plus... pinkish halo.
Akos Baranya
Active member
I would say the unique benefit of LED lighting is bulb cost going away as a factor. Most COB are rated for 40-50000 hours operating time, if you compare to say a 2.5k HMI, you would need to swap bulbs up to 100 times. Even if we take half of that, that is 10000$ saving on an equivalent LED.
ofc, there aren't too many equivalent LEDs atm. I'm working on an LED array with 1000W power (not 1k equivalent, 1k real), I'll post it when it's done, should be pretty bright.
ofc, there aren't too many equivalent LEDs atm. I'm working on an LED array with 1000W power (not 1k equivalent, 1k real), I'll post it when it's done, should be pretty bright.
Retrospective
Well-known member
Hi MattinSTL, Have you done any comparisons yet with the Arri 300w? Been wanting to purchase the 120t and put it on a Chimera Pancake. Not sure if it would be bright enough to punch through it.