July 22, 2014, 05:45:16 AM

Author Topic: LED light panels  (Read 7386 times)

CJRodgers

  • EOS M2
  • ****
  • Posts: 198
    • View Profile
LED light panels
« on: April 15, 2011, 11:37:34 AM »
If you were to buy an LED light panel for continous lighting whilst filming,  what would be your minium requirments for it. I am thinking of building one but i want to know what colour temp and brightness are acceptable. Dont want to go through all the effort to find out its average! HA.

Also has anyone got any experience with filming with LEDs in in low light? Are they up to the job?

Thanks!

canon rumors FORUM

LED light panels
« on: April 15, 2011, 11:37:34 AM »

CR Backup Admin

  • Administrator
  • 1D Mark IV
  • *****
  • Posts: 751
    • View Profile
Re: LED light panels
« Reply #1 on: April 15, 2011, 06:04:23 PM »
I considered building one for my lighting table about a year ago, but finding high quality, reliable components was a problem, there were lots of expermenter grade LED's, but the good ones were hard to find.  A year has passed, and undoubtedly there are better parts available.  However, prices of good units have dropped as well.

The last time I saw them being used was when a motion picture was being filmed in my Father's nursing home a few months ago.  They put the unit close to a face to give it even lighting, probably about 3-4 ft max.  This was a $2K unit at the time.  They were still using many high powered conventional lights along with it, the led unit was just for the actors face.

check this article out, and let us know what you find or build, I'm certainly interested.

http://blog.vincentlaforet.com/mygear/lighting/

Lawliet

  • 7D
  • *****
  • Posts: 340
    • View Profile
Re: LED light panels
« Reply #2 on: April 15, 2011, 08:08:26 PM »
Also has anyone got any experience with filming with LEDs in in low light? Are they up to the job?

My selfbuilt panels for high speed photography work well - basically clusters of Cree XP-G, with each single LED having about the same continuous output as the video light Canon sells for their pro video cameras. Unit output more in the range of 1kw hot light, more then enough for filming if you don't have to overcome ambient light.

CR Backup Admin

  • Administrator
  • 1D Mark IV
  • *****
  • Posts: 751
    • View Profile
Re: LED light panels
« Reply #3 on: April 15, 2011, 09:30:49 PM »
Also has anyone got any experience with filming with LEDs in in low light? Are they up to the job?

My selfbuilt panels for high speed photography work well - basically clusters of Cree XP-G, with each single LED having about the same continuous output as the video light Canon sells for their pro video cameras. Unit output more in the range of 1kw hot light, more then enough for filming if you don't have to overcome ambient light.

Can you give some details of the power supply and construction?  What did it cost to put it together?

thedantay

  • Guest
Re: LED light panels
« Reply #4 on: April 16, 2011, 09:53:35 AM »
Not sure if this will help, but I bought a LED light off ebay. Made a simple video about it:
Small | Large

Though I do recommend getting more lights. Depends on what you want the lights for. But I really think this has more than enough power for what I want!

Lawliet

  • 7D
  • *****
  • Posts: 340
    • View Profile
Re: LED light panels
« Reply #5 on: April 16, 2011, 08:12:38 PM »

Can you give some details of the power supply and construction?  What did it cost to put it together?

11 coulums of 9 LEDs each, in a half inch grid. A metal core PCB for good heat dissipation, for usage as a flash its thermal capacity would be enough, as a video light two heat sinks intended for high end graphics cards helped...500W for 1µs is simpler then 100W for indefinite time.
Groups of 3 LEDs each get their own driver, for a forward voltage of about 10V, a powerFET as a constant current source, powered by a 12V lead acid battery, buffer caps and charging current limiter don't do a thing for constant illumination.
As a video light its a wasteful design, driving the LEDs at just about 1/4 their rated power because they are to tightly packed and using linear regulation - but thats just a secondary use... :)

Overall costs in the 1500€/$ range, but if you want just a video light you could get away with the new XM-L LEDs and about 25€/$ per 100W of tungsten filament. Thats if you buy enough parts to get past the markup of low volume dealers.

For inspiration: take a look at a Fenix TK35/41 for what a single Cree XM-L can do, or a TK45 to give you an impression of 3 XP-Gs. Both give you ~3 stops more then the average video light. 8)

CJRodgers

  • EOS M2
  • ****
  • Posts: 198
    • View Profile
Re: LED light panels
« Reply #6 on: April 19, 2011, 04:37:59 AM »

Can you give some details of the power supply and construction?  What did it cost to put it together?

11 coulums of 9 LEDs each, in a half inch grid. A metal core PCB for good heat dissipation, for usage as a flash its thermal capacity would be enough, as a video light two heat sinks intended for high end graphics cards helped...500W for 1µs is simpler then 100W for indefinite time.
Groups of 3 LEDs each get their own driver, for a forward voltage of about 10V, a powerFET as a constant current source, powered by a 12V lead acid battery, buffer caps and charging current limiter don't do a thing for constant illumination.
As a video light its a wasteful design, driving the LEDs at just about 1/4 their rated power because they are to tightly packed and using linear regulation - but thats just a secondary use... :)

Overall costs in the 1500€/$ range, but if you want just a video light you could get away with the new XM-L LEDs and about 25€/$ per 100W of tungsten filament. Thats if you buy enough parts to get past the markup of low volume dealers.

For inspiration: take a look at a Fenix TK35/41 for what a single Cree XM-L can do, or a TK45 to give you an impression of 3 XP-Gs. Both give you ~3 stops more then the average video light. 8)

Sorry i didnt fully follow this, is this just for a flash or for continuous use aswell? Im looking to make a continuous LED panel for lighting during filming.

What cd rating where these LEDs? Also what colour temp? Also have you found anything that suggests how to place teh leds for maximum coverage whilst mainting brightness. For example would a ring arrangement be better than a grid of LEDs?

I have found some ultra bright LEDs that cost about £1 each, so i dont think the whole project should cost more than £150 hopefully including battery although i need to do some research on that.

I havent worked out values im just collecting ideas. But mine will definately be for a rechargeable battery only as i dont want the cost or weight of a transformer, plug, rectifier, extra fuses, more capes etc that would all come with using mains supply.

LEDs and LED drivers are dirt cheap, and for the powersupply i will just a regulator, something like the lm317 as its adjustable but i need to check the amp rating. Ill use some big caps for smoothing, something like 100uf electrolytic and some diodes such as 1n4004 to protect the circuit from being reversed (battery connected the wrong way around)

I litterally just need somthing that inicates the sort of brightness i need and the best layout. Ill go have a look at the stuff out there i guess and just copy their specs?


..I might make it usuable with mains as a seperate junction box, fitting the transformer etc in the junction box rather than with the LED panel.
« Last Edit: April 19, 2011, 04:45:52 AM by CJRodgers »

canon rumors FORUM

Re: LED light panels
« Reply #6 on: April 19, 2011, 04:37:59 AM »

NormanBates

  • 6D
  • *****
  • Posts: 490
  • www.similaar.com
    • View Profile
    • www.similaar.com
Re: LED light panels
« Reply #7 on: April 19, 2011, 04:54:48 AM »
I suggest you look at the lighting section of the dvxuser forum, and ask there if you don't find your answers:
http://www.dvxuser.com/V6/forumdisplay.php?27-Lighting

CJRodgers

  • EOS M2
  • ****
  • Posts: 198
    • View Profile
Re: LED light panels
« Reply #8 on: April 19, 2011, 07:13:53 AM »
brilliant thanks!,

and @lawliet, sorry didnt read your first post! sounds great for a flash, those leds are very powerful.

adrianjuaneli

  • SX50 HS
  • **
  • Posts: 1
    • View Profile
Re: LED light panels
« Reply #9 on: April 16, 2014, 04:19:45 AM »
The person who wants the best lighting system at best for your budget, they undoubtedly select the led bulbs. It will be available at low prices with a wide range of color combinations. It will be also an advantage in the selection. Could you please provide the best available source of led bulbs and its latest information.

optical design

drjlo

  • 6D
  • *****
  • Posts: 611
    • View Profile
Re: LED light panels
« Reply #10 on: April 20, 2014, 12:18:54 AM »
How about 3000 lumens of Samsung LED, softened, at $135?

https://www.indiegogo.com/projects/mighty-mini-photo-video-dream-light#home

Lawliet

  • 7D
  • *****
  • Posts: 340
    • View Profile
Re: LED light panels
« Reply #11 on: April 20, 2014, 12:37:53 AM »
How about 3000 lumens of Samsung LED, softened, at $135?

As an experiment: get a simple construction light, with a 240W/300W R7s rod it gets you about 5000lm. Best practices for softening involves bouncing it of something; keeping saftey distances(as stated on the lights) and material heat tolerances in mind. Shouldn't cost you more then having pizza delivered.

tcg films

  • SX50 HS
  • **
  • Posts: 5
    • View Profile
    • TCG Films
Re: LED light panels
« Reply #12 on: April 20, 2014, 01:29:24 PM »
Please let us know how it goes and post some pics.

canon rumors FORUM

Re: LED light panels
« Reply #12 on: April 20, 2014, 01:29:24 PM »