Using Gels...onboard light

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DVX100Shooter

Veteran
Up to this point I have always used gels to splash some colored light onto a dull white wall for some flavor. Or to accent something in the background of a shot. I recently purchased a LED on board light from Vidled which came with several gels. The one I have on the light now is a clear gel (not sure of formal name) but I use it soften the light a tad bit more in conjunction with the dimmer. Now also in the gels pack are several what look like Amber (Full CTO); 1/4 Cto and 1/2 Cto which look a light amber down to a light peach type color. Are those gels used to color correct? When should I be using those type gels over the non colored gel I have on there now?

Am I supposed to use the Amber looking gels when using the light outside at 5600K and the others for indoor shooting at 3200K? I can completely not use them as well but I got the super bright LED light and let me tell you that thing is very bright with no gels on it! LOL!
 
Since you got Amber(yellow) gells with your Vidled, i assume you got the 5600K(daylight) Vidled model. So, use your Amber gells whenever you use your light in indoor places, especially when other tungsten light sources are present. In other words, amber gells will convert your lighttempetrature from 5600K to 3200K to match with other 3200K light sources...
 
No I got the 8200k coolLed-40. So if I use the amber (orangish) gels indoors then should I use the other (clear diffused) gels outdoors?
 
Full CTO will reduce the color temperature of the source by about 2400 degrees Kelvin. If your LED source really is an 8200K device, then full CTO will get you down to near a daylight balance. It would take double full CTO to get you anywhere near tungsten. There are only a very few situations where an 8200K light source wouldn't need to be warmed up at least a bit; perhaps a very overcast day in open shade might be the only place that you could use this uncorrected, but I can't imagine that a LED source would have enough punch to be useful on exteriors.

Are you really certain that this is an 8200K source? This just doesn't make much sense for a cinematic light source.
 
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www.vidled.com the info is right there...I have the information that came with my light sitting right here as well and it says the Color Temperature is 8200K. I have the coolLED-40.

I was shooting a celebrity softball game tonight and I used it outside during the day. The sun was still up but it was closer to Dawn and I had the light on while doing some interviews and it looked nice.
 
I got the coolLED too. Their website spec also says that with the 1/2 CTO gel, the colour temperature is about 5400K. Take those figures as very approximate. I'll try and get a light meter on mine tomorrow and get some actual readings.

However, if you're shooting video, you can just eyeball it. If it looks too blue, put a stronger orange gel on it! I found it to be useful as a fill light and adds a sparkle to the eye on daylight exteriors, and two were brilliant as the only sources on an exterior night shoot I did where mains powered lights were not an option.
 
Well, had a play with an old, out of calibration date, Minolta Chroma Meter and the results are a not straightforward.

The CoolLED colour temperature is a bit angle dependent. On-axis the temperature is higher than if the Vidled is pointed slightly off the metering dome!

The CoolLED with no gel measured from about 9500K to 10000K+ !!
With 1/2 CTO it varied less, but averaged about 5800K
With Full CTO it averaged about 3800K

So, perhaps unsurprisingly, it doesn't behave quite like a tungsten incandescent source when measured with a meter designed for measuring incandescent lights. Its spectrum due to it deriving white by using a blue or UV LED to excite a phosphor has peaks and troughs not present in light from a hot filament, albeit without the nasty green spikes in uncorrected fluorescents. A different light meter would probably give somewhat different colour temp readings.

The angle dependence seems to be a feature of the physical construction and physics of current white LEDs, where the exciting radiation takes different paths through the phosphor depending on what angle you look at it.

In short, any colour temperature specs measured with a standard light meter are very approximate and useful only as a guide. If you shoot on video, just gel it by eye, on film do tests with the intended filmstock.

However, in actual use with video, it has worked fine as a white light source with appropriate gels. To the eye and the camera, the bare CoolLED looks blue, but not as blue as the measured colour temp would suggest!
 
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Thanks Eric for that great description (and sorry for not chiming in earlier; I've had login woes).

You are pretty much bang on right with what you posted. Many who don't own a VIDLED will dismiss the coolLED-40 as being too blue in its colour temperature.
But in use, this is not really an issue, as one can use gels, as you and others suggest. And if the coolLED is the only light source one can effectively white-balance to it.
We could have made the lights using a permanent CTO gel, but that simply would have meant that we would have limited the lights' brightness somewhat. Don't forget, these cool LEDs are MUCH brighter than normal 5mm LEDs, and offer a great beam angle. There are LEDs that are [close to] 5600K, but they are NOWHERE NEAR as bright, or offer similar evenness in their beam angle.. It's a trade-off for sure.

I've used the lights myself on a couple of documentary films, and like you suggest, it normally is best to use the lightest CTO that gives acceptable results; and this is most conveniently achieved by eye.

We are updating our gel pack, and it will include (in addition to the current gels) a lighter diffusion material (Rosco 101) and some 1/4 CTB, and some Green also.

And: I am liking the VIDLEDs when they are non-5600K sometimes. Just to give a splash of color to a subject, hence the reason why we'll be including the CTB and green also, starting in a few weeks.

All I can say is, everyone who bought one is satisfied......so far! :)
 
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