White LED, crazy idea... or not?
 

I have this cute little white LED flashlight and was thinking about building a panel of white LEDs and trying that as a portable light for ENG-type work. Then searching around the 'net I found a whole range of flashlights which use white LED technology... even one with 60 LEDs and a nice hand grip, advertized as good for underwater video. Any chance this can be good for general videography? Is this kind of light really full spectrum and usable with the white balance available in semipro DV cams? Is flourescent better for some reason?

Here is a link: http://www.theledlight.com/trek6000.html

They are the lighting system of the future, go for it!

I looked into this a while back.

What you suggest is already available on the market.

At nearly $5 per LED in small quantities, these lights are generally high priced for do-it-yourselfers.

Still, they could save on battery expenses and weight.

Charles Papert, I believe, used one on 'West Wing' and provided a link to the manufacturer recently.

Does anybody know of availability of white LED lights in the Vancouver, BC area? Perhaps a store that sells scuba diving equipment...

It has been said that you can buy the LEDs on ebay for a lot less than the stores charge.

Try there.

Yes Mike, it has been said, but I don't have easy access to a credit card at this moment and my sister will be in Vancouver for a short time frame, so shipping dates can be a problem (has been in the past). I would much prefer to buy, in this case, one of those waterproof multi-LED things designed for underwater use from a specialized store in the area.

Try a sporting goods shop. Any place that sells weapons and gear to the police will also have the LED flashlights.

I'd try electronic surplus stores.

Scott

Look at this bulb replacement
 

DB640-0IW-014M is the part number at $76 per. 40 white LEDs per bulb. Meant for automotive bulb replacements.

http://www.ledtronics.com/

Here's an interesting article

http://users.telenet.be/cisken/LED_r...ringlight.html

Wow, look at THIS ONE! :
http://www.ledtronics.com/ds/gdl002-200/

Try and get some Nichia's if your going with the small ones. I've found the white they produce mmm.. less brown.
Some guy made a cool light using a sony camcorder battery on dvxuser.com, no 'resistance' needed because the battery is 7.2 volts so wire 2 in series and those in parralell (if memory serves me). You need a plate adapter for the battery, if anyone knows where to get such a thing please post.
I find these lights to give a hard shadow line and the light they produce to be diffrent looking than normal light. Can make a great effect. An add-on diffuser might help. Happy soldering, fun project!

This one isn't bad for those who want to light inside vehicles:

http://www.ledtronics.com/ds/PLT100/

Brookstone has it
 

Hi

Your local Brookstone might have something thats usable. I am trying to get one as a part of my guerilla lighting kit.
Take a peek at: http://www.brookstone.com/shop/product.asp?product_code=446716

NEW 20 LED Worklight

Brookstone sku # 446716

Super-bright worklight has 20 powerful LEDs and a pivoting head to deliver the right light in the right direction. Super-extended battery life means light works for 80 to 160 hours continuously. Rugged plastic/rubber construction makes it even more versatile. Two modes of operation: 10 LEDs provide bright, broad light; 20 LEDs provide ultra-bright area light. Durable LEDs never need replacement because they’ll last more than 100,000 hours of continuous use. Rubber on/off switch makes light easy to activate. Uses three D batteries (not included).

Well - Kaiser has made it too
 

This little beautie uses 1 (one) led to create the equivalence of a 8 W halogen. And it runs on AA batteries. Adorama has it.

------------------------

3282
KAISER: „digiNova“ LED Video Light
Super compact camcorder light using LED
technology.
White high-performance LED combined with
facetted reflector and cylinder diffusor for
even light distribution. Light intensity comparable
to 8 watt halogen light.
Powered by four regular AAA-batteries or
rechargeable NiMH batteries.
Accessory shoe with blocking screw.
Specifications:
Oprating voltage: 4,8 - 6 V
Color temperature: approx. 5.500 Kelvin
Operating time with set
of batteries/charge: up to 2 hours
LED service life: up to 200,000 hrs
Weight (w/o batteries): 60 g (2.1 oz.)
Dimensions (WxHxD): 47 x 80 x 57 mm
(1.9 x 3.1 x 2.2 in.)
Supplied without batteries.

www.litepanels.com

Some issues with LEDs
 

I spent a fair amount of time on the phone with one of the LED light panel manufacturers.

There are some interesting issues with using LEDs:

1. They have a very sharp demarcation between the area they light and the area outside the illuminated circle. It is a very sharp cut-off, not like an incandescent lamp with its gentle fall-off.

2. The shadow cast by the LED light falling on an object tend to be rainbow colored rather than the gray that would be cast by an incandescent lamp.

3. LED light output is highly sensitive to input voltage. For example, a LED panel rated for 12 to 14 volts input power will only deliver its rated amount of light at 14 volts. At 12 volts it is significantly less.

4. The colder the white (higher color temp), the more light a LED puts out. As they approach Cool-White color temp, the light output has gone down because the phosphor coating has to be made thicker to bring down the color temperature.

5. A white LED is generally made by using a blue LED to excite a phosphor coating to emit the white light.

6. The high-powered LEDs, the 1 watt LEDs, may not be suitable for video lighting according to my source. He said that while they are great for stop light and panel light applications, the methods used to create the apparently high output won't work with a CCD sensor. I think he means that the bright LEDs are driven with a pulsed, not a DC power and that the pulses may be detected by our cameras.

I may have one of those 198 LED panels to test in the next few weeks. I'll keep you informed.

I'm told I'll be able to get my hands on one of thise big panels this week. I'll keep you informed.

I"ve seen pictures taken with and without this lamp outdoors with a digital still camera and they look OK.

Tomorrow I'll get my hands on the unit and take some pictures with my PD150.

Great Mike, please do keep us in the loop. Thanks.

OK, played with the big panel and some other interesting lights.

The big panel does exactly what I want except:

They way they wired it, there are 3 LEDs in series and then each string of 3 is in parallel with other strings to make up the light.

This causes a problem. Each LED requires 3.8 volts to 'fire'. With 3 in series, the string requires 11.8 Volts to fire. What this means is that a 12 volt battery belt or 12 volt lead acid battery will not last long before the panel turns off. That's because battery voltage 'droops' over use. Lead Acid being worse than NiCads or LiON or NMH cells.

So, instead of my 85 watt battery belt being able to power the panel for 6 hours or so, it will only run it for about the same, or perhaps lower number of hours that the belt will run my DSR-300 before it complains of a low battery.

May have to get a 14.5 volt battery belt or use the big LiONs from my DSR-300.

At least that is what I think it means. I'm trying to find a reliable source of discharge curves for my belt.

BTW, they also have a 400 LED panel ($750) as well.

It does put out a reasonable amount of light. Exactly what I'd want for filling shadows and popping colors. The LEDs are noticably cream-colored (warm white, 3000 degrees K) compared to the cool white of the 'normal' LEDs.

I like the panel a lot.

However, it is very popular all of a sudden and they are back-ordered. Probably take 2-3 weeks to get one now.

I also saw some 40-LED lights in the lamp configuration that is used in slide projectors and NRG lights. So we plugged it into my NRG light and promptly smoked it. Don't know why since the light is not polarity sensitive. Possibly the pulsed source is what caused the problem. That light is quite reasonable for use as a fill light for video.

More later

As a quick fix, since I am leaving for a shoot in Pennsylvania next week, I've purchased 2, 7-LED Flashlights that will run for about 150 hours on 4 AA cells.

I removed the light module and inserted 2 softgels between it and the front plastic lens. This gives a nice smooth light for the distance and angle at which I'll be shooting. Since these are fill lights only, not main lights (the exhibition hall has lots of light, all from the overhead but just not good enough for good color on vertical surfaces and nooks and cranies.

Now all I have to do is machine a carrier for the lights to fit on top of the PD150. Later I'll probably mount the light module in something smaller for the camera and place the batteries somewhere else.

For use on a DSR-300, I could run both light modules off the built-in power tap on the camera.

LEDs are costing nothing, so if you like to grab you solder iron.
http://www.superbrightleds.com
and even cheaper
http://www.lsdiodes.com/5mm/

and if you do not like the idea of putting together hundreds of LEDs, try the luxeon stuff.
http://shop.dotlight.de/shop/index.p...8ac6425a642bc9

Right, except grabbing the soldering iron has its own cost too. My most limited asset is time so purchasing, where costs aren't too out of line with the components makes a lot of sense.

A 198 LED array in an enclosure is worth $198 in my estimation. 40 LEDs in a M16 (projector) bulb configuration for $58 is also.

So far the only led panel i have seen was priced almost a thousand dollar, so if you know where to purchase around 300$ , il will be happy to read some references.

For $750, you can get a 400 LED panel here
http://www.ledtronics.com/datasheets/RGB.htm
Some assembly required. $198 for the panel I like.

the 198$ panel looks good , except the dead center that is pretty bad for video use.
the litepanel.com look great but 750$ for 160 leds it is about
4$ the led, so since you can get one for half a dollar, i think it still worth to grab the iron solder.

if somebody wants to start a business, he can even buy several thousand led for probably cheaper, add a printed circuit and sell the stuff as a kit.

<<<-- Originally posted by Giroud Francois : the 198$ panel looks good , except the dead center that is pretty bad for video use.

There is no dead center. The LEDs are evenly distributed. I've had that one in my hands.


the litepanel.com look great but 750$ for 160 leds it is about
4$ the led, so since you can get one for half a dollar, i think it still worth to grab the iron solder.

There are 400 LEDs in the $750 unit.

if somebody wants to start a business, he can even buy several thousand led for probably cheaper, add a printed circuit and sell the stuff as a kit. -->>>

I doubt it but go ahead and try!

OK, flashlight adapter #1.

Go to hardware store, get an 2" L-bracket (Stanley part # 75-6371), 2 x spring-loaded broom holders (Stanley part # 75-2025)for hanging brooms on wall. These are the type witha round spring arm and a plastic pad to grip the object in their jaws. Costco 7-LED flashlights fit in very nicely.

Mount broom holders to the L-bracket (one on each side) with 2 screws. You will have to drill one hole. I used 8-32 screws to fasten the broom holders to the L-bracket

Mount L-bracket on camera shoe adapter that has 1/4-20 stud.

Flashlights are now mounted side by side above the camera without interfering with CAC-12 microphone holder on Sony PD150.

I placed two disks of diffusing material and one disk of CC filter material on backside of lens cover, clamped between LED holder and lens cover. Warm White LEDs would be nicer than these Cool White LEDs.

Works very nicely.

Interesting, the LEDs get quite hot in constant use. Burn your hand on the inside metal power connectors hot. Have to turn them off from time-to-time.

Total cost for flashlights and bracketry - About $50.

Run-time is said to be about 140 hours per each load of 4X AA Cells.

Total weight, 1 Lb., 0.7 Oz.

I'm off to Pennsylvania on Friday to try them out.

The flashlights worked OK but I want a bit more power.

I've ordered the LEDTronics MR-16 warm white, 42-LED lamp. Now I'll build a good looking enclosure for it and set up for a battery. It is real tempting to use a pair of Sony LiON cells (or one of my DSR-300 LiON cells) to power it.

A major design issue is whether to mount the battery on the camera (it could be powered directly from the DSR-300 which has a power tap) or to use a remote battery. A single gel cell should power this lamp for quite a while at its maximum power consumption of 5 watts.

Any suggestions are welcome.

Received the LED light fixture (MR16-42-21W-014M) and a lamp socket (hard to find) and have found what will be the first enclosure.

Think I"m just going to power it straight from my NRG battery belt for now using a 4-pin XLR cable. Later I may mess around with two Sony LiON batteries in series to power it.

The lamp head will weigh about 6 oz without the cable.

Expect to have it operational by next week.

Pictures at 11

Quick update.

Put the lamp on my 65 watt, 12 volt NRG battery belt to check battery life.

That was 24 hours ago. Looks like it will run a minumum of another 24 hours. Guess I can downsize the battery!

You guys know that compact fluorescent bulbs make more light than an LED , watt for watt.
They make 12V compact fluorescent bulbs too. High frequency ballasts are recommended.

LED's might be great for small lights, or where damage might be a concern.

-Les

The problem with flo's is that they are too large to comfortably fit on top of a camera. Plus they require a high voltage power supply which LEDs do not. Energy efficiency isn't the ultimate goal.

LEDs tend to project their light forward since they have or can have a lens. So they tend to throw columnated light, sort of like a fresnel. Sharp fall-off on the edges of the beam. This is an advantage since I don't need a reflector to recapture the light that would otherwise escape to the side and rear.

Lots of reasons why LEDs are superior for my application. And I think, perhaps, even for studio use. I've now seen a light panel thinly populated with white LEDs and of a size to be a soft and broad light source that can be powered by something like a NP-1B for an hour or two. Or from a small wall wart.

You literally could make a broad LED light by pushing the LEDs through Foam board and then wiring up the pins to accomodate the power supply you want to use.

Need incandescent and daylight balance? Just make the panel with both 3500 K and 6000K or 7000K LEDs. Turn on what you want.

Matter of fact, if you wanted to spend the money for a flexible circuit board (expensive), you could roll your LED light panels up and put them in a tube for shipping. Then pin them up or hang them from a clothes hanger for use.

Taking it to the extreme, Because LEDs can be very small, how about the equivalent of wall paper that you glue on a wall? Now you have a very broad and soft light.

Have you looked into tiny DC to DC converters that take you from 7.2V to aprox. 14V?

Not yet. I'm probably going to power the lamp from my battery belt for the next exhibiton or from the power tap on my DSR-300 camera.

Got a source for Sony LiON battery sockets? I'd hate to have to build them after examining the spring-loaded blades that socket into the female pins on the batteries.

Of course I could just disassemble one of my battery chargers!

Haven't looked for thoughs Sony batteries but I was able to find one for my DVX100 battery. Im looking all over the place for that DC to DC converter. I need to take 7.2V / 1600mAh and take it up to around 14V at a 12w/1 Amp draw for the LED lights. Anyone know where to find one?

try
http://www.power-one.com/ (former swiss melcher company)
while converting from 7.x volt seems not very easy to find (usual range are 3V, 5V 12V)
see http://www.datel.com/data/power/uwr14-20wa-series.pdf

dc-to-dc converters can be real inefficient... avoid if at all possible.

i would be looking to power a small led panel with some kind of off-the-shelf nimh battery solution, maybe a d-cell setup... nimh is phenomenal, it retains full voltage during the discharge curve, and it's gotten real cheap in the standard flashlight battery sizes.

I just bought a LiON pack that will work very nicely. Should run the lamp about 30 hours or so.

I couldn't find a DC to DC converter that would accept 6 volts in, a voltage which would be convenient to supply.