Filters for bi-color LEDs at DVinfo.net

William Hohauser · February 5th, 2014, 08:14 AM

What would the proper gel filter number be to balance my bi-color LED lights with both sets of lights on (56 & 32k) to daylight? Or indoors? The light itself claims to be putting out 40k when both sets are at full.

Noah Yuan-Vogel · February 7th, 2014, 10:50 AM

1/2 CTB but in reality that's a waste of time since 1/2 CTB loses 1-stop so it'll have the same effect as just turning off the 3200k LEDs and it's likely the filter will exacerbate any CRI issues or green/magenta spikes. You'd basically just be doubling the power consumption and color spike for the same light output.

William Hohauser · February 7th, 2014, 11:50 AM

Thanks. I am just looking towards a shoot where I know I'll be competing with large picture windows and I rather not have a blue cast from the windows.

John Nantz · February 7th, 2014, 01:04 PM

After playing around with LEDs for awhile, I've come up with a few ways of dealing with the olor issues. Realize I - am - no - colorist, so this has been a trial-and-error effort that gives me something I can live with.

One set is the 120V powered CoolLights CL-LED600 5600ºK and these seem to look best gelled with a 1/4 & 1/8 magenta gels in order to get white looking the best I can. Even so, it isn't perfect, just "good enough". These fixtures have the little LEDs.

The other light, which I really like, is the battery powered Comer CM-LBPS1800b and it has two different color temperature LEDs for what they say is 4500ºK. There are only, I think, 10 LEDs but they are large and really put out the light. This is my go-to light for getting more natural looking colors. For non-critical shooting (and not being a colorist, or even good at it) I don't bother to do any color correction with this one. If there is a mix of light, say fluorsent, or daylight, or all of the above, this light can overpower the other light to give a pleasing and acceptable picture. The Comer has a built-in magenta filter but while I've tried it, so far I've never used it.
Comer CM-LBPS1800 On-Camera LED Light (Sony Battery) | L.A. Color Pros)

My understanding is the Comer is a knock-off of a Sony light.

With the CoolLights, I'm using them either gelled, and I'd agree with Noah on the light loss) and/or used as a fill light and overpowered with some other light, for example, sunlight or the Comer.

If the subject can be lit with the sunlight coming through the window then one option may be to use the LED as a fill and not as a main light. This way the light balance issues, hopefully, shouldn't be as big of a problem. The little LEDs seem to have a very uneven color output, that is, with unwanted spikes.

William Hohauser · February 7th, 2014, 03:31 PM

It's a crap shoot with the way the weather has been around here. The LEDs will likely be a key with the indirect sun coming in the windows acting as a backlight. The windows will not be in the shot and they are not curtained. If I had really bright 56K LEDs I wouldn't be asking but I guess I'll find a decent medium that I can color correct later.

Tom Morrow · February 7th, 2014, 11:56 PM

1/2 ctb will get you into the ballpark, but you might end up dimming the blue LEDs so much that the extra punch from the orange LEDs doesn't buy you anything. Maybe 1/4 ctb since you seem more concerned about light output than color temp.

February 5th, 2014, 08:14 AM	#1
William Hohauser Inner Circle Join Date: Dec 2005 Location: New York City Posts: 2,650	Filters for bi-color LEDs What would the proper gel filter number be to balance my bi-color LED lights with both sets of lights on (56 & 32k) to daylight? Or indoors? The light itself claims to be putting out 40k when both sets are at full. __________________ William Hohauser - New York City Producer/Edit/Camera/Animation Last edited by William Hohauser; February 5th, 2014 at 09:48 AM.

February 7th, 2014, 10:50 AM	#2
Noah Yuan-Vogel Major Player Join Date: Dec 2004 Location: New York City Posts: 613	Re: Filters for bi-color LEDs 1/2 CTB but in reality that's a waste of time since 1/2 CTB loses 1-stop so it'll have the same effect as just turning off the 3200k LEDs and it's likely the filter will exacerbate any CRI issues or green/magenta spikes. You'd basically just be doubling the power consumption and color spike for the same light output.

February 7th, 2014, 11:50 AM	#3
William Hohauser Inner Circle Join Date: Dec 2005 Location: New York City Posts: 2,650	Re: Filters for bi-color LEDs Thanks. I am just looking towards a shoot where I know I'll be competing with large picture windows and I rather not have a blue cast from the windows. __________________ William Hohauser - New York City Producer/Edit/Camera/Animation

February 7th, 2014, 01:04 PM	#4
John Nantz Trustee Join Date: Jun 2010 Location: Seattle WA Posts: 1,252	Re: Filters for bi-color LEDs After playing around with LEDs for awhile, I've come up with a few ways of dealing with the olor issues. Realize I - am - no - colorist, so this has been a trial-and-error effort that gives me something I can live with. One set is the 120V powered CoolLights CL-LED600 5600ºK and these seem to look best gelled with a 1/4 & 1/8 magenta gels in order to get white looking the best I can. Even so, it isn't perfect, just "good enough". These fixtures have the little LEDs. The other light, which I really like, is the battery powered Comer CM-LBPS1800b and it has two different color temperature LEDs for what they say is 4500ºK. There are only, I think, 10 LEDs but they are large and really put out the light. This is my go-to light for getting more natural looking colors. For non-critical shooting (and not being a colorist, or even good at it) I don't bother to do any color correction with this one. If there is a mix of light, say fluorsent, or daylight, or all of the above, this light can overpower the other light to give a pleasing and acceptable picture. The Comer has a built-in magenta filter but while I've tried it, so far I've never used it. Comer CM-LBPS1800 On-Camera LED Light (Sony Battery) \| L.A. Color Pros) My understanding is the Comer is a knock-off of a Sony light. With the CoolLights, I'm using them either gelled, and I'd agree with Noah on the light loss) and/or used as a fill light and overpowered with some other light, for example, sunlight or the Comer. If the subject can be lit with the sunlight coming through the window then one option may be to use the LED as a fill and not as a main light. This way the light balance issues, hopefully, shouldn't be as big of a problem. The little LEDs seem to have a very uneven color output, that is, with unwanted spikes.

February 7th, 2014, 03:31 PM	#5
William Hohauser Inner Circle Join Date: Dec 2005 Location: New York City Posts: 2,650	Re: Filters for bi-color LEDs It's a crap shoot with the way the weather has been around here. The LEDs will likely be a key with the indirect sun coming in the windows acting as a backlight. The windows will not be in the shot and they are not curtained. If I had really bright 56K LEDs I wouldn't be asking but I guess I'll find a decent medium that I can color correct later. __________________ William Hohauser - New York City Producer/Edit/Camera/Animation

February 7th, 2014, 11:56 PM	#6
Tom Morrow Major Player Join Date: Feb 2011 Location: San Francisco, CA Posts: 416	Re: Filters for bi-color LEDs 1/2 ctb will get you into the ballpark, but you might end up dimming the blue LEDs so much that the extra punch from the orange LEDs doesn't buy you anything. Maybe 1/4 ctb since you seem more concerned about light output than color temp.