# Help designing DIY lighting for film/video



## Briankauf (Feb 27, 2014)

Hello folks,

I've been spending some time around the CP forums for a few weeks, upon the recommendation of folks at dvxuser.com, a forum for digital video enthusiasts and professionals. I am working to construct some portable lighting for video, and my understanding is this is one of the best places around for advice on DIY projects, especially regarding LEDs. 

Normally, I use high-end fluorescent lighting for my video work, which produces excellent results (the fluorescent side of video/film has been in development for probably 20 years or so) due to excellent high-end bulbs and ballasts that lead to a near-perfect match to either daylight or tungsten lighting (the "standards" in the film world). 

LED lighting is still in many ways, a young product. I have constructed LED light systems for coral reef aquariums, but none yet for video. The issues I am most concerned with are color match, light "throw" and controllability (not so much dimming, but the ability to shape the light, a la a fresnel lens).

Recently I have been looking in to remote phosphor lighting panels, and I think this may offer my best best for building high-quality LED lighting panels. My understanding is they typically offer a little better quality of light, in terms of spectral output than even the highest quality bins of "white" LEDs. 

I have two goals in my lighting build and any advice would be wonderful! 

1.) Create 2-3 1' x 1' (approx.) light panels to project soft (diffuse) light at either 5600K or 3200K (ideally I would build a pair for each color temp). I have two directions I can go with this, I can either attempt to buy high-quality white LED lights at 5600K or 3200K and build traditional light panels (similar to this "budget" offering http://www.fvlighting.com/store/lighting/led/k4000.html. Or, I can build a remote phoshor system by source LEDs at 565nm and using a Remote Phoshor sheet from either PhosphorTech, Intermatix, or Cineo. 

2.) Create 2-3 LED fresnel-like lights, at something like the equivalent of 500W tungsten. For this to work, I would need as small a source as possible, with enough power as possible (again, RP could potentially work, at the expense of possibly softening the light, which is not ideal. The issue is finding high CRI lights at the correct CCT at 50 or 100W. Ideally, I would also source optics to focus this light a bit before it hits the fresnel lens. 


In both cases, I could use advice on sourcing LEDs and drivers (capable of taking 12V or 14.4V power and converting it to the appropriate voltage and amperage for a string of LEDs) and any advice on heatsinks, housings, and optics.

Thanks!!

Brian


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## videoman (Mar 1, 2014)

A warm welcome to CPF Brian. A very useful conversion tool calculator http://ledstuff.co.nz/data_calculators.php will show that the light in question in your #1 goal will output 2400 lumens. That lumen rating can easily be accomplished with a few Cree XM-L2's in a proper heat sinked enclosure. The leds may have TIR optics in the 20 to 40 degree beams which can easily be diffused if needed. The advantage is also the capability to have a narrow beam when needed. A great driver would be the H6CC from Taskled that can easily supply 6 amps to the leds from DV sources up to 24 volts and can easily be dimmed with a 50K audio taper pot. Those 2400 lumens is approximately equivalent to a 150 watt filament bulb in brightness. Perhaps not bright enough for your purposes.
Phosphor panels ? A little tricky as the "mixing chamber" must be designed right and will require many ultra-blue leds ( Cree XT-E's as an example). Heat management is paramount here. Them XT-E's get mighty hot, especially a few dozen needed for a 5000 lumen light. Not to mention tooling, trial and error, frustration, sourcing PET material etc, etc. 
For DIY, I would stick with white leds.


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## Briankauf (Mar 1, 2014)

Thanks for the info!

In regards to the second goal, the fresnel, I am realizing the RP route may be a bit harder than expected. The issue for me is that I don't see any high powered (100W+), high CRI arrays that come in the "correct" CCTs of either daylight (5600K) or tungsten (3200K). From Cree, I can get the XLamp series (CXA3050) in 3000K or 5000K, but that may be hard to mix with my other lighting. Bridgelux's large offerings also seem limited to 3000K or 5000K. Any other options I may be missing? 

I would like to go with a single smallish source to best get a hard light source, or at least, as close an approximation as possible.


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## videoman (Mar 1, 2014)

Bridgelux has a 5600K in 29 volts fV, runs at 2.9 amps delivers 10K + lumens ( that's like a 600w filament) 

http://www.bridgelux.com/wp-content...-Bridgelux-RS-Array-Data-Sheet-2014.01.27.pdf

The CRI is 70 though. The Hyperboost driver shoud take care of that nicely.


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## Briankauf (Mar 1, 2014)

videoman said:


> Bridgelux has a 5600K in 29 volts fV, runs at 2.9 amps delivers 10K + lumens ( that's like a 600w filament)
> 
> http://www.bridgelux.com/wp-content...-Bridgelux-RS-Array-Data-Sheet-2014.01.27.pdf
> 
> The CRI is 70 though. The Hyperboost driver shoud take care of that nicely.



Ok, in a quick read on the Hyperboost driver, I don't see any mention of it changing the light quality of LEDs -- do you have a link for me on how it would help improve CRI?


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## DIWdiver (Mar 2, 2014)

He meant the Hyperboost should drive the part well, not that it should alter the CRI. I've never seen any discussion on improving the CRI of an existing LED. There's some discussion of how to get good CRI, but never by altering a white LED, at least that I've seen.


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## Briankauf (Mar 2, 2014)

DIWdiver said:


> He meant the Hyperboost should drive the part well, not that it should alter the CRI. I've never seen any discussion on improving the CRI of an existing LED. There's some discussion of how to get good CRI, but never by altering a white LED, at least that I've seen.



Ok, that makes more sense to me. Unfortunately, I don't think I'd want to go with lights with such low CRI, even if the CRI scale is a rather limited measure of light quality.


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## WeLight (Mar 2, 2014)

Briankauf said:


> Thanks for the info!
> 
> In regards to the second goal, the fresnel, I am realizing the RP route may be a bit harder than expected. The issue for me is that I don't see any high powered (100W+), high CRI arrays that come in the "correct" CCTs of either daylight (5600K) or tungsten (3200K). From Cree, I can get the XLamp series (CXA3050) in 3000K or 5000K, but that may be hard to mix with my other lighting. Bridgelux's large offerings also seem limited to 3000K or 5000K. Any other options I may be missing?
> 
> I would like to go with a single smallish source to best get a hard light source, or at least, as close an approximation as possible.


The CXA does come in 5700K in min 80 CRI, your probably better to go with 5000k in typ 95 CRI version


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## videoman (Mar 2, 2014)

I came across many videographers that find the 5000K color a tad too warm for their daylight fill. That is why I ditched the Cree MTG-2 and went for the XM-L2's. They are very picky and particular about the color rendition. I only wished the MTG-2 came in cooler flavors just for that reason. The Hyperboost is really in a class of its' own considering the ability to have a 3.2A output and driving to 80V, as well as being dimmable and compact. I have made many prototypes with the low CRI cool versions of the XML/XMl-2 and did not have any issues with off-color casts. I did however see a small but noticeable difference in the 3000Kish variety between the 90 CRI's as compared with the 75-80 ones. Hard to describe but preferable in video output to monitor and face colors. What I also want to see is a 24 volt 3A led (75W) which would be ideal with the Hyperboost from a 14.4 V DC LiIon brick.


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## jeffosborne (Mar 7, 2014)

White LED's with lesser CRI values can be improved by adding red and cyan LEDs to the mix:

http://www.candlepowerforums.com/vb...Rebel-LED-flood-light-with-red-and-cyan-boost

Jeff


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## chaosdsm (Mar 10, 2014)

Not sure what kind of LED's, driver, etc... they may be using, but Lumos with variable CCT from 3200K - 5600K, claims up to 98CRI with their LED lighting: I know it's not DIY, but perhaps, some research might turn up some useful info on what they use & how they build to further your ideas???

*300MK* 50W / 400W Tungsten Equiv. 12" x 12"
CRI 98 @ 3,200K
CRI 95 @ 5,600K 
1,100 lux @ 3.3' (1.0 m) @ 3,200K
1,200 lux @ 3.3' (1.0 m) @ 5,600K 

*500MKL* 120W / 800W Tungsten Equiv. 20 x 13"
CRI 98 @ 3,200K
CRI 95 @ 5,600K 
2,000 lux @ 3.3' (1.0 m) @ 3,200K
2,300 lux @ 3.3' (1.0 m) @ 5,600K 

*700MKL* 200W / 1500W Tungsten Equiv. 29 x 18"
CRI 98 @ 3,200K
CRI 95 @ 5,600K 
6,400 lux @ 3.3' (1.0 m) @ 3,200K
7,200 lux @ 3.3' (1.0 m) @ 5,600K


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## Briankauf (Mar 10, 2014)

Cool products from lumos. I haven't been able to dig up any info on which LEDs they are using.. But at that price point, i would guess they are hand selecting their LEDs at a premium. Perhaps they buy large quantities and pick out those examples that fit their needs...

as for the mixed colors.. I would fear that i would have a really hard time hitting the perfect balance without some high end equipment. I used mixed color leds fornmy reef lighting and i am still fine tuning the color mix a year later


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## Briankauf (Mar 11, 2014)

Alright, so I am getting my parts list together, and I would LOVE a double check from you fine folks.

Here is my plan - I will build 6 LED lights in total, 3x at 5000K and 3x at 3000K.

Parts:

1.) Enclosure/Heatsink - Each one will use a 6" MakersLED enclosure/Heatsink. I used these for my reef aquarium lights and loved them.
2.) LEDs - 3000K - CREE XM-L2 Bin: *[url]http://www.cutter.com.au/proddetail.php?prod=cut1711&cat=176*[/URL]* 
5000K - CREE XM-L2 Bin: T6 - Voltage per LED: 3V Amperage: 3A **[url]http://www.cutter.com.au/proddetail.php?prod=cut1624*[/URL]* 
3.) Driver - For each enclosure, the voltage requirement would be 3V * 12 = 36V at 3A = 108W (though, I am intending to underdrive the LEDs a bit to make them operate a bit more efficiently, so we call it 100W). 
I am thinking the Hyperboost - At 100W it would require some active cooling (I'll use a silent-ish fan), but it has been done: [url]http://www.candlepowerforums.com/vb/showthread.php?318378-Too-bright...&p=3691548&viewfull=1#post3691548[/URL]
4.) Optics -- I am looking through the LEDIL stuff, but for this I am still a bit lost -- any suggestions for a nice tight (35 degree) even beam from each LED?

Thanks!!*


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## kbec (Sep 28, 2014)

I was thinking of the same type of thing you seem to be trying to do. I am looking to either make LED type Fresnel or just buy some of those As Arri tungsten clones.

I came across this and it may give you some ideas:
US Patent 8702255, look for it on google, if you are handy, it seems to give a good clue as to how some of these are designed. I just passed up some really nice cpu cooling fans I could have gotten for almost nothing, but I didn't pick them up. 

I have a little tungsten light that puts out enough heat to easily start a fire. Another reason I am kind of leary about the tungsten Fresnel.

Once I get sort of an idea what I need, I am thinking to just throw a filter on it. Lee filters makes some filters that I think would work to convert the "daylight" to tungsten temps. 

I don't really need the ability to change the led color. I just want to have lights I can use without spending $200-2000 per light.


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## kbec (Sep 29, 2014)

Upon looking further, if you go to the litepanels website, there is a page that has all their patent numbers, I think its patents.php . That would be a good starting point for someone trying to build these type of units from scratch, plus a lot of good design info for anyone interested.


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## LEDealer (Sep 29, 2014)

Briankauf said:


> Hello folks,
> 
> I've been spending some time around the CP forums for a few weeks, upon the recommendation of folks at dvxuser.com, a forum for digital video enthusiasts and professionals. I am working to construct some portable lighting for video, and my understanding is this is one of the best places around for advice on DIY projects, especially regarding LEDs.
> 
> ...




If you're planning on filming in HD, you could use LUXEON Z ES by Philips, which has 3000K 90 CRI and 5700K 90 CRI products available.

**EDIT**

I should also add that LUXEON Z ES is an undomed LED that can get you very small beam angles (you could probably achieve 15 degrees without an issue) at very good lm/W.


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