View Full Version : Indoor shots with a window in frame (mixed color temperatures)


Reese Leysen
June 17th, 2007, 08:55 AM
I'm struggling with indoor shots in our movie where there's a window in frame. How do I handle such situations where the white balance is set for indoor and I get ugly blue light from outside coming in? Thus far I'm doing tricky color correction to fix it, I'd like to hear if anyone here has better solutions, thanks!

Bill Hamell
June 17th, 2007, 09:44 AM
I just did this all day yesterday.
Our solution was to put ND on the windows and gel the lights with 1/2 CTB.
White balance and you are good to go. :-)

Bill

Reese Leysen
June 17th, 2007, 10:08 AM
I just did this all day yesterday.
Our solution was to put ND on the windows and gel the lights with 1/2 CTB.
White balance and you are good to go. :-)

Bill

I'm sorry, I'm not much of a tech-head in the lighting/cinematography department yet.

How do you put an ND just on the window? You mean a neutral density filter, right?

And I don't think we can easily gel our worklights :) . (zero budget filmmaking...)

Seth Bloombaum
June 17th, 2007, 10:37 AM
Sorry about the zero budget.

1/2 or 3/4 CTB (color temperature blue) balances your tungsten lights to daylight. A 20x24" (about half a square meter?) sheet that might cover 1 to 4 lights, depending, costs about $7 US.

An alternative, that is usually more expensive because of how much you need, is to cover the windows with CTO (color temperature orange) gel. This stuff comes in sheets or rolls.

Then there is the brightness of the window light. As Bill suggested, ND (neuteral density) gray gell can be used on the windows to bring the intensity down. This can be combined in one gel with CTO.

Reese Leysen
June 17th, 2007, 11:36 AM
Ah alright, thanks a lot for the info!

Sean Skube
June 17th, 2007, 02:40 PM
Don't forget about color correcting to help resolve the issue as well.

Bill Davis
June 17th, 2007, 03:22 PM
Some companies, (GAM, I think, but possibly others) make gels that combine CTO with ND in a single sheet or roll.

As bright as it is here in Phoenix, I use it reasonably often to treat exterior windows in otherwise tungsten lit sets.

FWIW.

Reese Leysen
June 17th, 2007, 05:19 PM
I see, and would CTB gels work with my standard 500w halogen worklights?

Glenn Chan
June 17th, 2007, 05:37 PM
Don't forget about color correcting to help resolve the issue as well.
Color correcting away mixed color temperatures isn't exactly easy. It's much better to get it right on set.

2- The standard method of gelling a light is to clip the gel to the barndoors using C-47s/clothespins (wooden). Lights emit A LOT of heat, so you should attach the gel vertically so the gel doesn't block the rising heat / you get ventilation.

http://efplighting.com/?Filters_and_gels

2b- You could somehow try adding barndoors to your light... but IMO you might as well find some deal on a professional light. They are more efficient, save you time, more controllable.

2c- As an alternative, you could build your own ghetto Kinoflo / "nano-light". There's video instructions on how to do this in Victor Milt's Light it Right DVD (see vasst.com). It gives you a soft light, which is generally more useful than hard light. You change color temp. by changing the bulbs.

2d- Or, you can just tape the gel onto a c-stand and shoot light through the gel. But this is not the greatest solution if you want to control the light.

Reese Leysen
June 18th, 2007, 02:50 AM
Excellent, thanks a lot guys. I think I'm gonna get a full CTB and some other CTB gels. I think I might need the full CTB because the halogen lights are really pretty warm.

Edit: any idea where I can get this fastest from Belgium?

Jimmy McKenzie
June 18th, 2007, 04:58 AM
I see, and would CTB gels work with my standard 500w halogen worklights?

Gels on bigbox store worklights can turn to an icky goo real fast. You also mentioned that you are going to hunt for full CTB because your lights are so hot. It's the amount of colour temp. shift from 3200 kelvin (tungsten) you need, not the heat amount from the lamp.

Best of luck! Keep firefighting tools nearby when using those 500w outdoor only appliances indoors....

Reese Leysen
June 18th, 2007, 08:48 AM
Gels on bigbox store worklights can turn to an icky goo real fast. You also mentioned that you are going to hunt for full CTB because your lights are so hot. It's the amount of colour temp. shift from 3200 kelvin (tungsten) you need, not the heat amount from the lamp.

Best of luck! Keep firefighting tools nearby when using those 500w outdoor only appliances indoors....


I know :) . I meant that the lamps give a very warm light.

And thanks about the firefighting tip, I forgot about that and it's really important.

Sean Skube
June 20th, 2007, 03:28 PM
Oops. Should have been clearer. I meant CCing as an additional tool, not a means to fix it on it's own.

Don Donatello
June 20th, 2007, 06:14 PM
beware that full CTB is going to knock down your tungsten lights approx 2 stops !! will there still be enough light left to do what you want it to do ?

as others have suggested you can put 85ND, 85ND3, 85ND6, or 85ND9 on your windows ... you should be able to get the size you need from a local gaffer at a better price then retail stores ...

for zero budgets .. still call your local gaffer and see if they have thrown out any used CTB ( or other colors) gel recently that may be in their trash or he might just have a old roll with your size window he would sell for cheap ??...

for a pic of 1k light with blue gel look at the thread
http://www.dvinfo.net/conf/showthread.php?t=96749
post #4 .. 2nd photo ...

for ND on windows look at photo #6 where actors are in front of window ..

Reese Leysen
June 21st, 2007, 09:48 AM
beware that full CTB is going to knock down your tungsten lights approx 2 stops !! will there still be enough light left to do what you want it to do ?

as others have suggested you can put 85ND, 85ND3, 85ND6, or 85ND9 on your windows ... you should be able to get the size you need from a local gaffer at a better price then retail stores ...

for zero budgets .. still call your local gaffer and see if they have thrown out any used CTB ( or other colors) gel recently that may be in their trash or he might just have a old roll with your size window he would sell for cheap ??...

for a pic of 1k light with blue gel look at the thread
http://www.dvinfo.net/conf/showthread.php?t=96749
post #4 .. 2nd photo ...

for ND on windows look at photo #6 where actors are in front of window ..

Great info, thanks a lot man.

But I'm afraid our budget reaches no further than a bunch of CTB's for the lights. The 500watt worklights are pretty heavy, they can go down a few stops, I take it the CTB's (full blue or 1/2 blue at times) will diffuse the light a bit so there won't be as much extra need for diffusion as without the CTB's? (if so, that saves a stop or two)

Good advice on getting CTO sheets as well... I have no clue where to find a local gaffer but maybe I can dig up something.

Seth Bloombaum
June 21st, 2007, 11:04 AM
...I take it the CTB's (full blue or 1/2 blue at times) will diffuse the light a bit so there won't be as much extra need for diffusion as without the CTB's? (if so, that saves a stop or two)
Not to any useful degree. If you wanted diffusion before, you'll still want it.

Heiko Saele
July 4th, 2007, 06:41 AM
Full CTB cuts a lot of light (like 75% I think)
In most situations a 3/4 CTB will be enough to match the daylight.
I usually use 1/2 CTB only and white-balance to the daylight. This gives my lights a warm touch which is pretty nice and it leaves roughly enough light output (and I'm talking about 800W and 1k halogens...). Never underestimate the power of daylight, even if it's just a small window...

Nino Giannotti
July 4th, 2007, 11:07 AM
There are easier ways to get around these situations especially when time and budget is an issue. A lot depends on your schedule. Keep in minds that the outside light is unpredictable; it constantly changes and if you have a long shoot and consistency is important gels or no gels you might run into problems. Every year I do a dozen video projects for international resorts around the Caribbean and South America, I’ve been doing it for the last 20 years. These are good shoots but we don’t have the luxury to start gelling windows or travel with extensive equipment. For our interior shots we build our schedule around the existing light. There’s about an hour in the morning and another at night where the brightness of the outside light matches the interior light and also the color temperature gets very close thus requiring a minimum of gelling on the lights. This is the time that we do all the shots that must be blended with daylight and has been working very well for 20 years and hundreds of shoots.

Reese Leysen
July 5th, 2007, 02:54 AM
Thanks a lot for all the great feedback :) .