Color Temperature; Gels

T

tommygdawg

Well-known member
Hello everyone,

I have a question that's been on my to-do list to figure out in depth for a while. I have a very rudimentary understanding of color temperature, that is, I know the basics to get a certain look. But, I don't really know how to manipulate color temperature to achieve lighting that really stands above run-of-the-mill. The biggest problem I have is when to gel and when not to gel. Assuming I'm using gels, what colors do I want/need? All the lights I have are tungsten, and look very tungsten. When do I want to gel these and what colors should I use? I have CTB, but when do I really want to use it? Should I mix it with other colors? I know that the first answer will be "it depends on the scene." I know this, but what are some techniques you all use for achieving different looks with color temperatures and gels?

- Tommy
 
When you have all tungsten lights and you want to balance them to the daylight coming in use full ctb. You can get away with half, if you don't mind a little warmth from the tungsten lights.

But you can also just gel all the windows with full CTO instead. CTB is a pretty dense gel and tungsten lights aren't the most efficient, so usually this is the better way to go if you don't have a lot of big windows.

You can use plus and minus green for flouros. Usually the ones you find in homes or offices have a green spike so you can either gel those with minus green, or gel all your lights with plus green.

You can also use these color correction gels for mood. Gel lights coming in through the window for a moonlight effect or during the day gel them a little CTO to make things a little warmer and happier.

Hope that helps! Should be enough to get you started.
 
Thanks for the insights, it's much appreciated :) I've already got some CTB, so I'll get some CTO to complement it. Are there specifics in green I should get as well? I always wondered why shooting under fluorescent everything came off a nasty green even though in person they look blue.
 
I'd recommend some CTS (Straw) gels. They're sort of amber-orange and give a nice warmer feeling than putting CTO on a tungsten unit. I usually chuck them on the daylight flouro china ball units, so 5500k-ish -> Straw. Not sure what i'd use for tungsten based sources, maybe 1/4 straw, but that's just speculation.
 
One thing I discovered is that I actually prefer 3/4 CTO on windows to full CTO. Full can make them even warmer than tungsten lights.
 
hi tommy

get yourself a lee filters swatch book for their gels

these have a sample of the colours available and wavelength curves for each gel

they are a great way to study whats available and are available free from suppliers

cheers
 
In addition to what others have said, you can use gels to create mood too-- blue usually registers as night/moonlight, so maybe get a strong backlight with a blue gel on it (I've noticed that no blue gel, having everything white at night gives a gritty realistic feel. If you're doing a cop show or a documentary-feeling, I'd skip the blue). You can also use gels to add more color depth to a scene-- some variation in background color can help add a little depth.

Red or orange, even yellow works for candlelight (I've used all three, it depends on the scene. Dark and scary candlelight gets red, soft candlelit dinner gets yellow, etc.). Green seems freaky and is used a lot for sci-fi (but go easy on it, it's a little overdone... and it's really a big departure from the colors you normally see). Red creates a scary mood for your bad guys or for horror scenes. Of course, anytime you're putting a gel on something, make sure to have a few lights NOT gelled so the gels actually register as being colored (no use having everything red if there's no white to compare it to)!

But of course... it all depends on the scene.

One note, I've found that red or pink seems like it would work well for romantic scenes-- it doesn't. It just looks weird. Go for yellow to get a warm feel if you're wanting romantic. That's just IMO, but try it out and see if you agree.



A final note on gels-- almost all rental houses will have some gels that they'd probably give you for free if you ask. Buying gels is a fool's game (or someone on a deadline or with someone else's money)... make it a point to stop by some rental houses every few weeks and start building up a nice collection.
 
This is a very informative post.

I have a question, once you start mixing different colour temperatures for creating a cinematic mood, how do you handle white balance on a digital camera?

For example, in Martin Scorcesses's film "Hugo", main characters usually have a orangy/warm key and fill light, and a cyan rim/back light, how would you go about white balancing it on set?
 
tommygdawg said:
Hello everyone,

I have a question that's been on my to-do list to figure out in depth for a while. I have a very rudimentary understanding of color temperature, that is, I know the basics to get a certain look. But, I don't really know how to manipulate color temperature to achieve lighting that really stands above run-of-the-mill. The biggest problem I have is when to gel and when not to gel. Assuming I'm using gels, what colors do I want/need? All the lights I have are tungsten, and look very tungsten. When do I want to gel these and what colors should I use? I have CTB, but when do I really want to use it? Should I mix it with other colors? I know that the first answer will be "it depends on the scene." I know this, but what are some techniques you all use for achieving different looks with color temperatures and gels?

- Tommy
Click to expand...

There's a difference between gelling for color temperature and gelling for effect.

Gelling for color termperature is often straight-up color-correction, as in, you're changing the color of the light to fix a problem or a mismatch. You do this because your light sources are different color temperatures.

Then there's gelling for color grading, which is gelling for effect rather than to fix something.

They can overlap some, but if you're worried about color temperature, you're usually correcting rather than grading.
 
David Jimerson said:
There's a difference between gelling for color temperature and gelling for effect.

Gelling for color termperature is often straight-up color-correction, as in, you're changing the color of the light to fix a problem or a mismatch. You do this because your light sources are different color temperatures.

Then there's gelling for color grading, which is gelling for effect rather than to fix something.

They can overlap some, but if you're worried about color temperature, you're usually correcting rather than grading.
Click to expand...

Good point, I guess I'm interested in the best way to go about both.

Thanks all for the info and the tips, they've been very useful and helpful. I love every little bit that I can use to learn and improve :) Thanks again!
 
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