How much would you pay?

No more than 1000.... for atleast an 1000w open face equiv, though it should be a fresnel. The price tags on current LED tech is a freaking joke. My dad had bloody LEDs lying around in his workshop in the 80s and they were dead cheap. Only thing that changed is that someone thought "hey... the movie guys likes using this, and Hollywood spends a lot of money... let's make them extremely expensive!" I don't buy into the crap that they are that costly to produce and if it's not the designers / producers who are making the money, it's the producers of the components. The world is full of greedy bastards......
 
Cheers for the replies. Im currently developing a simple fixed color temp led array system with matching battery system. either 3200k or 5600k temp. it is likely to be more of a 'flood' type open face light source with barn doors. due to the multiple diode array+ diffuser, will a fresnel lens be required?

i got estimated prices around £500 for a light head and lithium battery pack for 1hr continuous. additional 1hr battery packs would be around £120

Maybe I'll develop them and offer them on a hire basis to guerrilla type film productions without the means to cart around generators to off grid locations
 
" it is likely to be more of a 'flood' type "

A fresnel lens is not required if you are making it "unfocusable", that is as a non variable beam angle unit. It would be extremely difficult to incorporate a fresnel to multiple leds. A fresnel usually works best with a single point light source at a very precise predetermined distance. For it to work properly, a mechanical positioning system must be incorporated to move either the fresnel or the led back and forth in relation to each other to obtain the desired beam angle. Since you are using a multi led design, and wish to have a flood spread, then there are 3 ways one can accomplish that using leds. With diffusion, with reflectors, with TIR optics. All three methods will produce a floody beam but diffusion will cut down on the brightness the most. Reflectors come in a variety of beam angles from extremely narrow 10 degree to a wide 70 degrees and more. So do TIR's ( total internal reflection). The diffuser can also be used in conjunction with the reflectors/optics to spread the light even more or for glare control. There are diffusion panels made especially for leds such as the Makrolon by Bayer. If ultimate brightness is required, I would go for the reflectors. Depending on the leds you will be using, there are reflectors made by Ledil that are small and fit the larger size leds. Check their site for compatability. A great choice for the leds is the Cree XM-L as it adapts well with a wide range of optics and reflectors and is the most efficient led out there. It also comes in color temp. from 2700K all the way to 8500K. There are also high CRI leds available by Nichia, model 219, but the color temp is in the neutral 4000K variety. For a 1K filament equivalent, you will need serious thermal management as the leds do get hot. A large heat sink and perhaps active cooling will be needed. As a rough guide, perhaps 24 Cree XM-L's with Ledil Boom wide reflectors (50 degrees) along with 4 constant current drivers will be needed. Depending on the battery voltage used as well as the w/hr rating, there are other factors to consider in calculating the run time at full 1K brightness. I myself have made a 1K led unit using only 6 leds with TIR's, but the beam angle is 30 degrees and when widened up with diffusion, drops to a 350 watt halogen equivalent. Far from 1K
brightness.
 
You cannot compare a simple open face luminaire with a Fresnel - tungsten or Fresnel. Totally different quality of light. Open face, as in Redheads go BLAM - they pour a lot of light into the area. You can set the angle, and trim it with barndoors, but whatever you do, they do not blend gently with another. Fresnels, on the other had have a nice gentle roll off to the beam, and blend well with others for really even lighting. Their barndoor cut off is much nicer too. So for quality of light, a Fresnel is the artists expensive natural fibre paint brush and the open face unit the cheap artificial brush you buy at the DIY shop for painting a big wall quickly. Both have their place.

Over the past few months I've changed my opinion on LEDs from being dim and overpriced to something that can do the job. The colour is still a bit of a problem, but getting better. Brightness is so difficult to assess because many advertising specs are heavy on smoke oil and low on proper parametric data. So few give light output at X distance. The light linked to seems to fall into snake oil territory - although the critical thing is diegocervo likes it!
This revolutionary LED Fresnel is equipped with a 90 W Powerled array.
Extremely light (carbon fibre).
Extremely low power consumption (90 W) and high light efficiency (1000 W).​
Click to expand...

​
If it has a 90W array, it cannot have a power consumption of 90W - as "(tm) you canna change the laws of physics, Jim" , and a high efficiency of 1000W makes no sense. You could say produces a similar output to a 1000W tungsten unit.

This is a great price though, and the DMX input to me could be really good - however, I've not seen any UK versions yet.

Last night I used 12 LED moving heads that I mixed in with my 575W discharge sources. They were brighter, cheaper and half the weight - I may well invest in some of these myself.
 
LED light is just so ugly it has to be a "it's the only option" situation. "In the middle of the woods" kind of thing. When you are in that situation they are a lifesaver (lights that can deliver on battery power), but for general use.. eh.
 
Every one I've ever seen.
I feel the same about Fluoro. First choice is always Tungsten interior and HMI exterior, after that it's a compromise for budget or logistics. Sometimes you have to make that compromise, but if there is a way to light it with tungsten we will always light it with tungsten.
 
I couldn't agree more, gonzo! I'm a tungsten guy. They're the most versatile lights on the planet and they're fairly inexpensive, even for fresnels.
 
Norman99 said:
Which "ugly" leds have you seen/tried ? Let me guess...the Chinese ones..yes ?
Click to expand...

Have a read... silly forum wont let me post a link for some reason.

Anyways, find Guy Holts article on generators and LEDs, you'll understand why a lot of people still are not keen on LEDs just yet.
 
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Well every light has it's place, including fluorescent and LED.

I am currently refinishing the floor in my studio, so we are shooting talking head green screens in a much smaller area in the mean time for TV commercial work. Aside from the backlight/kicker, we have been lighting with Biax fluorescent lights which as well as providing a nice soft light on the talent, also help to keep the small space cool. 4K watts of Tungsten light would kill us in this small space. I like Tungsten lights as much as the next guy, but it's a matter of choosing the right tool for the job at hand.

All the Best!

Dave
 
Absolutely. When you need that battery powered fluoro to throw some key on a guys face in the middle of the woods or whatever you'll be damn glad you have it. I just view them as specialty purpose tools.
 
diegocervo said:
Is it a led light? As far as I understand it's tungsten.
If you're looking for a led with fresnel lens, give a look at this http://www.adcom.it/product/30980_DAYLED+1000.html
I bought the 650w version last week and I think it's really nice.
Click to expand...

Diego, the Lupolux stuff looks very interesting. Could you give us a more detailed review by any chance?

I'm wary of the claim of equivalent output to a 1000w tungsten because Arri claim their L7-C LED fresnels are equivalent to 750w tungsten, and they have a 220w fixture (compared to just 90w in the lupolux DayLED 1000 unit).

If the output is good though, I could certainly see myself adding a few of these to my kit.
 
Grug said:
I'm wary of the claim of equivalent output to a 1000w tungsten because Arri claim their L7-C LED fresnels are equivalent to 750w tungsten, and they have a 220w fixture (compared to just 90w in the lupolux DayLED 1000 unit).
Click to expand...

That is my main concern also. I am just skeptical that the photometrics of these lights are truly "Equivalent" to the tungsten wattage lights that they say. I have done a lot of photometric measurement of a variety of lights and found that output at shorter distances vs. longer distances is not necessarily a pure function of the wattage rating of a light. Fixture and bulb design are really important also. I just think that, with the CURRENT STATE OF THE TECHNOLOGY, an LED light that actually matches the photometrics of a tungsten light like a 1K Fresnel would cost very much more than the equivalent tungsten light. If it could be done, it would be way out of my price range.
 
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